• Title/Summary/Keyword: oblique

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A Study on the Accuracy Evaluation of UAV Photogrammetry using Oblique and Vertical Images (연직사진과 경사사진을 함께 이용한 UAV 사진측량의 정확도 평가 연구)

  • Cho, Jungmin;Lee, Jongseok;Lee, Byoungkil
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.39 no.1
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    • pp.41-46
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    • 2021
  • As data acquisition using unmanned aerial vehicles is widely used, as one of the ways to increase the accuracy of photogrammetry using unmanned aerial vehicles, a method of inputting both vertical and oblique images in bundle adjustment of aerial triangulation has been proposed. In this study, in order to find a suitable method for increasing the accuracy of photogrammetry, the accuracy of the case of adjusting the oblique images taken at different shooting angles and the case of adjusting the oblique images with different shooting angles at the same time with the vertical images were compared. As a result of the study, it was found that the error of the checkpoint decreases as the angle of the input oblique images increases. In particular, when the vertical images and oblique images are used together, the height error decreases significantly as the angle of the oblique images increases. The current 『Aerial Photogrammetry Work Regulation』 requires RMSE (Root Mean Square Error), which is the same as GSD (Ground Spatial Distance) of a vertical image. When using an oblique images with a shooting angle of 50°, a result close to this standard is obtained. If the vertical images and the 50° oblique images were adjusted at the same time, the work regulations could be satisfied. Using the results of this study, it is expected that photogrammetry using low-cost cameras mounted on unmanned aerial vehicles will become more active.

Morphological and Biomechanical Study of the Pulley System of the Thumb

  • Kim, Ji-Won
    • Physical Therapy Korea
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    • v.12 no.4
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    • pp.33-40
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    • 2005
  • The purpose of this study was to define more precisely the anatomy of the thumb flexor pulley system and to determine the relative contribution of each of the pulleys to the biomechanics of thumb motion at the metacarpophalangeal (MP) and interphalangeal (IP) joints. For this, 22 hands from 11 cadavers were used and randomly assigned to two groups. In the first group, the first annular (A1) pulley was cut first followed by the variable annular (Av) pulley and then the oblique pulley. In the second group, the oblique pulley was cut first followed by the, pulley and then the Av pulley. In 7 of 22 hands, it was a transverse structure parallel to the, pulley with a gap between the A1 and Av pulleys, referred to here as type I. In 9 hands, the A1 and Av pulleys were connected without any gap (type II). In 6 hands, the space between the A1 and Av pulleys were triangular in shape with fibers of the Av pulley converging toward the radial side (type III). In biomechanical study of both first and second experiments, there was no significant difference in MCP joint flexion between the all intact, A1 section, A1/Av section, A2 intact (A1/Av/oblique section), and no pulley configuration (p>.05). In occurring displacements less than 10 mm, there was no significant difference in IP joint flexion (p>.05). However, there was a significant decrease in IP joint flexion occurred in both 15 mm and 20 mm excursion (p<.05), when the oblique pulley was resected additionally after cutting the A1 and Av pulleys in first experiment, and when the A1 pulley was resected additionally after cutting the oblique pulley. According to the results, the injury of only the oblique pulley does not decrease thumb motion significantly. The oblique pulley injury with both the A1 and Av pulleys laceration decreased thumb motion significantly. The additional laceration of the A2 pulley does not decrease thumb motion.

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Effect of the Oblique Fluoroscopic Approach for Performing Stellate Ganglion Block (성상신경절 차단 시 빗김법의 효과)

  • Park, Chan Hong;Lee, Do Seok;Kim, Bong Il
    • The Korean Journal of Pain
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    • v.19 no.1
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    • pp.68-71
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    • 2006
  • Background: Stellate ganglion block (SGB) is a selective sympathetic blockade that affects the head, neck and the upper extremities. It is an important method that has been frequently used in pain clinics due to its wide range of indications. But there were some problem with performing SGB at C6 or C7. Thus, various techniques have been recently introduced to successfully perform SGB; among them, there is the oblique approach. This study was performed to evaluate the effectiveness of the oblique approach for performing SGB in C7. Methods: Forty six patients with sudden hearing loss were studied. In group I, the patient underwent C7 oblique SGB with 1% mepivacaine (3 ml) under fluoroscopic guidance. In group II, the patients underwent the C7 classical anterior approach SGB with 1% mepivaine (5 ml) under fluoroscopic guidance. We compared the occurrence of Horner's syndrome, the side effects and the changes of temperature of the skin of the hand. Results: The rate of Horner's syndrome was 81.5% in the group I and 84.2% in the group II. The rate of incurring increased skin temperature (${\geq}34^{\circ}C$) of the fingers was 77.7% and 79.4% in each group, respectively. Conclusions: The C7 oblique approach for SGB showed the same SGB effect compared with the C7 anterior approach for SGB, and there were also fewer complications. We conclude that C7 oblique SGB may be a beneficial method for treating patients with this particular malady.

Functional Relationship between the Vestibular Canals and the Extraocular Oblique Muscles (미노반규관(迷路半規管)과 외안사근(外眼斜筋)의 기능적(機能的) 관계(關係)에 관(關)하여)

  • Kim, Jeh-Hyub
    • The Korean Journal of Physiology
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    • v.6 no.2
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    • pp.49-56
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    • 1972
  • This experiment was designed to explore specific functional relationship between the vestibular canals and the extraocular oblique muscles by observing the isometric tension responeses of the muscles to the selected vestibular canal excitation. The vestibular excitation was simulated by either stimulation of the individual canal nerve or endolymphatic fluid displacement in each canal. Each canal nerve was subjected to square wave pulses with a monopolar wire electrode placed closely to the ampullary nerve endings for electrical stimulation, and a fine stainless cannula was introduced into the each canal toward the ampulla and a minute amount $(0.5{\sim}3.5\;microliter)$ of fluid was injected in or ejected out by means of a microsyringe connected to the cannula to produce ampullopetal or ampullofugal displacement of endolymphatic fluid. The superior oblique muscle was contracted by the excitation of homolateral canals and was relaxed by contralateral canals. On the contrary, the inferior oblique was contracted by the contralateral canals and was relaxed by the homolateral canals. Summation of excitatory and inhibitory canal effects from the bilateral vestibular system was demonstrable on the tension changes of the oblique muscles. Excitation of either dual or triple canals of the unilateral vestibular system also caused summation effect on the tension response of the oblique pair; thus multiple signals from the different ampullary receptors seems to be converged into the relevant ocular motor muclei. Since the superior and inferior obliques are known to receive their motor fibers from the contralateral trochlear nuclei and intermediate nuclei of the homolateral oculomotor complex respectively, the above experimental evidences indicate that the ocular motor nuclei for oblique muscles receive excitatory signals from the contralateral vestibular canals and inhibitory signals from the homolateral canals.

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The Study of Anticipatory Postural Adjustments in Voluntary Arm and Leg Movement (수의적인 상·하지 움직임 동안의 체간의 선행적 자세조절 연구)

  • Jung, Kyoung-Sim;Shin, Won-Seob;Chung, Yi-Jung
    • Physical Therapy Korea
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    • v.15 no.2
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    • pp.30-37
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    • 2008
  • Anticipatory postural adjustments are pre-planned by the central nervous system (CNS) before the activation of agonist muscles in the limbs, and minimize postural sway. Most previous studies on this topic have focused on upper-limb movement, and little research has been conducted on lower-limb movement. The purpose of this study was to investigate the recruitment order of left and right trunk muscles during limb movement. Fifteen healthy subjects (10 male, 5 female) were enrolled. Electro-myographic signals were recorded on the muscles of: (1) deltoid, lumbar erector spinae, latissimus dorsi and internal oblique during shoulder flexion, (2) rectus femoris, rectus abdominis, external oblique and internal oblique during hip flexion. During right upper limb flexion, the onset of left erector spinae muscle and left internal oblique muscle activity preceded the onset of right deltoid by 8.09 ms and 19.83 ms, respectively. But these differences were not significant (p>.05). A similar sequence of activation occurred with lower limb flexion. The onset of left internal oblique muscle activity preceded the onset of right rectus femoris muscle by 28.29 ms (p<.05). The onset of right internal oblique muscle activity preceded the onset of left rectus femoris muscles by 23.24 ms (p<.05). The internal oblique muscle was the first activated during limb movement. Our study established the recruitment order of trunk muscles during limb movement, and explained the postural control strategy of the trunk muscles in healthy people. We expect that this study will be used to evaluate patients with an asymmetric recruitment order of muscle activation due to impaired CNS.

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A Study on Effectiveness of Weight in Analytical Positioning of Oblique Photography (경사사진(傾斜寫眞)의 해석적(解析的) 위치결정(位置決定)에 있어서 경중율(輕重率) 적용에 관한 연구(硏究))

  • Yang, In Tae;Kwon, Hyon;Yeu, Bock Mo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.4 no.2
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    • pp.143-150
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    • 1984
  • This paper is a study on effectiveness of weight in analytical positioning of oblique photography. Oblique photographies are more economical than normal photographies as it has a larger ground coverage and as it can be applied in situations where objects of interest are difficult to be approached. But the comparatively complex methods involved, present a problem in obtaining the desired results. In view of this fact, analytical rectification was applied in normalizing the oblique photographs. As oblique photographies are extensively used in slops and mountainous regions, a number of difficulties are encountered during the control surveying. The photocoordinates of the oblique photographs, taken at $30^{\circ}$, were weighted during rectification. They were weighted as inversely proportionate to the derived formular of ${\gamma}_y=f{\cdot}tan{\frac{\theta}{2}}+y_a$, the distance of each point from the isocenter along the Y axis. By applying the weights, coordinates errors conld be reduced and the error difference between oblique and normal photographs could be reduced upto 53.2%.

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Estimation Method for Ice load of Managed Ice in an Oblique Condition (깨어진 해빙의 사항조건에서 빙 하중 추정법 연구)

  • Kim, Hyunsoo;Lee, Jae-bin
    • Journal of Ocean Engineering and Technology
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    • v.32 no.3
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    • pp.184-191
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    • 2018
  • Recently, as sea ice in the Arctic has been decreasing due to global warming, it has become easier to develop oil and gas resources buried in the Arctic region. As a result, Russia, the United States, and other Arctic coastal states are increasingly interested in the development of oil and gas resources, and the demand for offshore structures to support Arctic sea resources development is expected to significantly increase. Since offshore structures operating in Arctic regions need to secure safety against various drifting ice conditions, the concept of an ice-strengthened design is introduced here, with a priority on calculation of ice load. Although research on the estimation of ice load has been carried out all over the world, most ice-load studies have been limited to estimating the ice load of the icebreaker in a non-oblique state. Meanwhile, in the case of Arctic offshore structures, although it is also necessary to estimate the ice load according to oblique angles, the overall research on this topic is insufficient. In this paper, we suggest algorithms for calculating the ice load of managed ice (pack ice, 100% concentration) in an oblique state, and discuss validity. The effect of oblique angle according to estimated ice load with various oblique angles was also analyzed, along with the impact of ship speed and ice thickness on ice load.

Effect of Bridging Stabilization Exercises on Trunk Muscles Activity On and Off a Swiss Ball (교각운동 시 공 적용이 체간근 활동에 미치는 영향)

  • Kim, Moung-Jin
    • Physical Therapy Korea
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    • v.16 no.1
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    • pp.18-24
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    • 2009
  • The purpose of this study was to assess the effect of bridging stabilization exercises on trunk muscles activity on and off a Swiss ball. 20 healthy university students volunteered to participate in this study. Subjects were required to complete following four exercises: exercise 1, single bridging exercise; exercise 2, feet on ball bridging exercise; exercise 3, calf on ball bridging exercise; exercise 4, back on ball bridging exercise. Surface electromyography from selected trunk muscles was normalized to maximum voluntary isometric contraction. A repeated measures of ANOVA with post-hoc Bonferroni's correction was used to determine the influence of exercise type on muscle activity for each muscle and descriptive statistics was used to determine local/global muscle ratios. The rectus abdominis of exercise 4 showed significantly higher muscle activity than rectus abdominis of exercise 1, 2, 3 (p<.05). The external oblique of exercise 2, 4 showed significantly higher muscle activity than external oblique of exercise 1 (p<.05). The internal oblique of exercise 2, 4 showed significantly higher muscle activity than internal oblique of exercise 1 (p<.05). The erector spinae of exercise 2, 3, 4 showed significantly higher muscle activity than erector spinae of exercise 1 (p<.05). Median of internal oblique/rectus abdominis ratio of exercise 1 was 1.16, exercise 2 was 2.43, exercise 3 was 2.45, exercise and 4 was 1.27. Median of internal oblique/external oblique ratio of exercise 1 was 1.01, exercise 2 was .91, exercise 3 was .99, and exercise 4 was .93. Muscle activity can be influenced by addition of a Swiss ball in bridging exercises. It is recommend to use a Swiss ball for trunk stabilization exercise.

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Effects of Nonequilibrium Condensation on an Oblique Shock Wave in a Supersonic Nozzle of Constant Expansion Rate (팽창률이 일정한 초음속 노즐흐름에 있어서 비평형 응축이 경사충격파에 미치는 영향)

  • 강창수;권순범;김병지;홍종우
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.14 no.5
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    • pp.1311-1319
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    • 1990
  • For the purpose of preventing the flow undulation in the cascade of steam turbine, the blades are made into a constant expansion rate in static pressure. And the flow in those cascades is transonic or supersonic in the range of 0.7-2.0 in Mach number. As a consequence, an oblique shock wave, known as inner or outer edge shock wave, arises in the flow of cascades. Especially when the steam in cascades is in a state of high wetness, nonequilibrium condensation and condensation shock wave occur, and they give rise to an interference with oblique shock wave. In the present study the case of expansion of moist air through a supersonic nozzle of constant expansion rate, which behaves similar to that of wet steam, was adopted. The effect of nonequilibrium condensation on the oblique shock wave generated by placing the wedge into the supersonic part of the nozzle was investigated. Furthermore, the relationship between nonequilibrium condensation zone and incident point of the oblique shock wave, oblique shock wave angle, the variations of angles of incident and reflected shock waves due to the variation of initial stagnation supersaturation and the relationship between the height of Mach stem and initial stagnation supersaturation are discussed.

Comparative Study on Trunk Stabilizers Activity between Experienced Pilates Exercise during Hip abduction, Lift, Leg Swing Motion (필라테스 운동의 경험에 따른 엉덩관절 벌림, 리프트, 레그스윙 동작 동안의 몸통 안정화 근육 활성도에 미치는 효과 비교)

  • Lee, Youngjin;Choo, Yeonki;Oh, Taeyoung
    • Journal of The Korean Society of Integrative Medicine
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    • v.6 no.4
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    • pp.91-100
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    • 2018
  • Purpose : The study investigated the effects of Pilates exercise on strengthening trunk muscles of females who perform such exercise for the purpose of comparing activation of trunk muscles that contact while performing Pilates motions between females with or without at least 8 weeks of Pilates experience. Methods : The study investigated 10 females with at least 8 weeks of Pilates experience in the past 6 months (experienced group) and 10 healthy females without Pilates experience (non-experienced group). The study used basic Pilates postures involving hip abduction, lift, and leg swing motions as the measurement postures in comparing the activation of muscles used for stabilization, such as the rectus abdominis, external oblique abdominal, and transverse abdominis & internal oblique abdominal muscles. Surface electromyography was used for measuring muscle activation, and the measurements targeted activation of the rectus abdominis, external oblique abdominal, transversus abdominis, and internal oblique abdominal muscles. Results : The study results showed that, as compared to the non-experienced group, the experienced group had significantly higher muscle activation in the transverse abdominis and internal oblique abdominal muscles during hip abduction (p<.05) and significantly higher muscle activation in the rectus abdominis, external oblique abdominal, and transverse abdominis & internal oblique abdominal muscles during lift and leg swing motions (p<.05). Conclusion : Pilates exercise performed over a long period can be recommended as an effective exercise method that can increase the activation of trunk muscle, and especially, repeated performance of highly difficult motions can increase muscle activation even more, which can help promote spinal stabilization, prevent pain, and improve performance of activities of daily living.