• Title/Summary/Keyword: External and internal stability

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Design and Structure Analysis of a Tower Service Lift for Offshore Wind Power System (해상풍력발전시스템 타워서비스리프트 설계 및 구조해석)

  • Choi, Young-Do;Son, Sung-Woo;Jang, Ho-Choul;Choi, Nak-Joon
    • Journal of Advanced Marine Engineering and Technology
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    • v.36 no.1
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    • pp.101-108
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    • 2012
  • The purpose of this study is to establish a design method of tower service lift for offshore wind power system, as well as to conduct structure analysis of the service lift system. The service lift system will be built in the internal area of tower of the offshore wind power system. Design and structure analysis for the tower service lift system are conducted to clarify the stability and reliability of the system. Main objective of the design is to secure sufficient capability of transportation of workers and equipment with satisfactory performance within the designed tolerance limit. Total deformation and equivalent stress of the lift system by external load are examined using the results of structure analysis.

Charateristics of the Jointed Steel-Grid Reinforcement and the Application (결합강그리드보강재의 특성 및 적용)

  • Han, Jung-Geun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.5 no.3
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    • pp.15-22
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    • 2002
  • To analysis of the embanked slope stability using a jointed reinforcement, the internal stability and the external stability have to be satisfied, respectively. But, because the lengths of ready-made steel-grid were limited, the reinforcements must be connecting themselves to the reinforcing. In this study, the mechanical test was carried out to investigate the tensile failure and the pullout failure at the joint parts of them, which was based on the analysis of reinforced slope in field. Through the tensile tests in mid-air for the jointed steel-grid, the deformation behavior was seriously observed as follows : deformation of longitudinal member, plastic deformation of longitudinal member and of crank part. Those effects were due to the confining pressure and overburden pressure of the surrounding ground. The bearing resistance at jointed part of jointed steel-grid was due to the latter only. The maximum tensile forces were higher about 20kN~27kN than ultimate pullout resistance, but, the results of those was almost the same in mid-soil. The failures of steel-grid occurred at welded point both of longitudinal members and transverse members and of jointed parts. The strength of jointed parts itself got pullout force about 20kN, which was about 65% for ultimate pullout force of the longitudinal members N=2. To the stability analysis of reinforced structure including the reinforced slope, the studying of connection effects at jointed part of reinforcement members must be considered. Through the results of them, the stability of reinforced structures should be satisfied.

Stability Analysis of a Stereo-Camera for Close-range Photogrammetry (근거리 사진측량을 위한 스테레오 카메라의 안정성 분석)

  • Kim, Eui Myoung;Choi, In Ha
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.39 no.3
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    • pp.123-132
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    • 2021
  • To determine 3D(three-dimensional) positions using a stereo-camera in close-range photogrammetry, camera calibration to determine not only the interior orientation parameters of each camera but also the relative orientation parameters between the cameras must be preceded. As time passes after performing camera calibration, in the case of non-metric cameras, the interior and relative orientation parameters may change due to internal instability or external factors. In this study, to evaluate the stability of the stereo-camera, not only the stability of two single cameras and a stereo-camera were analyzed, but also the three-dimensional position accuracy was evaluated using checkpoints. As a result of evaluating the stability of two single cameras through three camera calibration experiments over four months, the root mean square error was ±0.001mm, and the root mean square error of the stereo-camera was ±0.012mm ~ ±0.025mm, respectively. In addition, as the results of distance accuracy using the checkpoint were ±1mm, the interior and relative orientation parameters of the stereo-camera were considered stable over that period.

A study on the Effects of Internal Customer Assistance Activity on Market Orientation and Customer Orientation (내부고객 지원활동이 종업원의 시장지향성과 고객지향성에 미치는 영향에 관한 연구)

  • Lee, Gun-Hong;Jang, Byeong-Jib;Yoon, Ji-Eun;Kim, Yong-Beom
    • Journal of the Korea Safety Management & Science
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    • v.14 no.3
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    • pp.245-257
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    • 2012
  • Business environment, competition among firms in recent years, diverse and fragmented by the symbol of the consumer has become very complex and intense. Nevertheless, for the best performance of firms differentiated their company strives to have unique core competencies. In this study, reviewing the internal customer support activities and existing research on market orientation and then how it affects the future strategy for the internal customer support activities. Through the results of this study, first, to appear understanding of the effect of education and training to customers in enterprise-wide, strategic plan through competitor analysis, improved communication between departments, etc need to design to be effective in performance of company in a long term when in planning and training for employees such as job training, service training and training for improving service mind. Second, employment stability and internal communications to the employee's customer orientation showed no significant affect. This is considered for employees due to lack of fear or anxiety, so the employer could focus on his role in the current organization willing to participate actively for goals of the organization. Finally external customer orientation in the employee's customer orientation did not affect the analysis results which is appeared to in companies are constantly communicating with employees through the company's position and the difference between the employee's position is necessary to look for ways to narrow down.

Effects of the Support Surface Condition on Muscle Activity of Abdominalis and Erector Spinae During Bridging Exercises

  • Hong, Young-Ju;Kwon, Oh-Yun;Yi, Chung-Hwi;Jeon, Hye-Seon;Weon, Jong-Hyuck;Park, Kyue-Nam
    • Physical Therapy Korea
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    • v.17 no.4
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    • pp.16-25
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    • 2010
  • The aim of this study was to determine the muscle activity of the abdominalis and erector spinae during bridging and unilateral bridging exercises on the firm surface, the sir-fit, and the foam roll. Eighteen healthy young subjects were recruited for this study. Surface electromyographic (EMG) activities were recorded from the both sides of the rectus abdominalis, external obliques, internal obliques, and erector spinae muscles during bridging and unilateral bridging-exercises. A one-way repeated analysis of variance was used to compare the EMG activity of each muscle according to the support surface condition. Differences in the EMG activities between the bridging and unilateral bridging exercises, and between the right and left side were assessed using a paired t-test. The study showed that the EMG activities of all of the muscles were significantly higher when the bridging exercise was performed using the foam roll or sit-fit than on the firm surface. The EMG activities of the right rectus abdominis, right external obliques, the right internal oblique, and both erector spinae were significantly higher during unilateral bridging ex exercise using the foam roll or the sit-fit than on the firm surface. The EMG activities of all of the muscles were significantly higher during the unilateral bridging exercise than during the bridging exercise. Based on these finding, performing the unilateral bridging exercise using the sit-fit or the foam roll is a useful method for facilitating trunk muscle strength and lumbar stability.

Study on Medical Thought of "Zhouyi Cantongxie(周易參同契)" ("주역참동계"에 나타난 의학사상 연구)

  • Im, Myung-Jin;Kim, Byung-Soo;Kang, Jung-Soo
    • Journal of Korean Medical classics
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    • v.24 no.5
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    • pp.1-10
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    • 2011
  • According to "Dongeuibogam(東醫寶鑑)", "the Shinnong Herb Bible(神農本草經)", "Chamdonggo(參同攷)", come to the conclusion about medical thought of "the Zhouyi Cantongxie(周易參同契)". Alchemy is a common field both on the eastern and western civilization, but a process of development is different. Ancient chinese alchemist made a study on external alchemy, but harmful consequences of external alchemy was consecutive, many scholars had turned their interest on internal alchemy which is related in human meridian biology and spirit. In the western alchemy has developed to make a study on analytic psychology and science of religion. Most importantly, the eastern and western alchemy have something in common what at the point of the perfection of self is similar, but the name is different, for example in the eastern alchemy we can be immortals and take a spiritual enlightenment with the elixir of life, in the western we can take a cure of souls as a christian. As for internal alchemy, "Cantongxie(參同契)" gives influence to the theories such as the theory of danjeon(lower part of the abdomen), evolution, aging, and life nurturing. Especially, the theory of danjeon shows such merit for studying since it is similar to triple energizers(三焦) and the theory of qi street(氣街) of oriental medicine. The study on "Cantongxie(參同契)" was achieved in Korea too, especially Chosun dynasty. "Candongkao (參同攷)" by Seo Myung-eung(徐命膺, 1716~1787) are representative. According to "Candongkao(參同攷)", Geon(乾), Gon(坤), Gam(坎), and Ri(離), the four trigrams for divination, each are affiliated with lungs, spleen, kidneys, and heart. Nowadays the study on alchemy correspond with modern trends, which are anti-aging and living without any disease. If processed mineral drugs is assured for stability, it can be used for incurable diseases such as cancer.

A Study The Structural Stability of the Fence Ohgokmun Soswaewon Factor Analysis (소쇄원 오곡문 담장의 구조적 안정에 미치는 요인 분석)

  • Jang, Ik-Sik;Jeon, Hyeong-Soon;Ha, Tae Ju;Lee, Jae-Keun
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.31 no.4
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    • pp.113-122
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    • 2013
  • In this study, the traditional structure of the impact on the stability analysis. Korean traditional landscape architecture column space of stonework stable composition as the foundation of the fence for a long time been known to fall down and not maintained. The destination of research Ohgokmun Damyang Soswaewon fence which is in harmony with nature is one of the traditional structures that affect its shape without being kept so far came true. This includes our ancestral wisdom and that wisdom can guess guesswork. But I let the traditional reproduction incidence structures frequently. This deviation from the traditional method of construction application of shorthand stand. Thus, the subject of this study, the factors that do not fall down fences Ohgokmun solution is to indirectly gain the weak. In addition, epidemiological studies and the methods of calculation of the inferred physical examination, the results of the analysis were derived through the following. First, the internal factors of the fence Ohgokmun constituting the structural member and the coupling of the scheme. 1) based on stable ground. Greater role in the country rock The fact that the settlement will have no symptoms. 2) to minimize the friction caused by hydrological water to remove the two-pronged process through stone work building form and menu sustaining power in hydrology and flooding made against the bypass channel. 3) due to the load bearing capacity and durability to withstand the strength of the material and the construction of structures in the form of a dispersion of power between each individual to maximize the process of getting traction was applied. Second, external factors Ohgokmun fence the results obtained through the calculation of the dynamics of repair, is greatly affected by the wind and the water gate of the fence, but the action of the structural stability of the lack of power that hurt enough conclusion. In this study, the results of the structure of internal and external influence as well through the structure can be viewed as composed consisting. However, over the next follow-up in terms of climate and environmental factors due to the fact that the fall might.

Effects of Modified Abdominal Draw-in Maneuver on Trunk Muscle Stability and Functional Capacity and Pain in Patients with Chronic Low Back Pain (수정된 복부 드로우-인 기법이 만성요통 환자의 몸통 안정성과 기능, 통증에 미치는 영향 -사례연구-)

  • Kim, Chang-Beom
    • PNF and Movement
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    • v.15 no.3
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    • pp.217-226
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    • 2017
  • Purpose: The purpose of this study was to determine the effects of a modified abdominal draw-in maneuver on trunk stability and functional capacity as well as pain in patients with chronic low back pain. Methods: The study included 3 patients with chronic low back pain who volunteered to participate. The modified abdominal draw-in maneuver included a posterior pelvic tilt, a traditional abdominal draw-in maneuver, and a vibration sensory feedback device. Voluntary abdominal contraction using the vibration sensory feedback device was performed by the subjects for more than 1 hour per day, 5 times per week, for 6 weeks along with common low back pain treatment. Electromyographic signals in the rectus abdominis (RA), external oblique (EO), internal oblique (IO), and erector spinae (ES) muscles were measured to compare muscle activation. The degree of pain was measured using the visual analogue scale (VAS), and functional capacity was measured using the Korea Oswestry Disability Index (K-ODI). All results were compared to the means before and after intervention. Results: After the intervention, the RA, EO, and IO showed increased muscle activation and the ES showed decreased muscle activation. The visual analogue scale decreased after intervention and the K-ODI decreased after intervention. Conclusion: Modified abdominal draw-in maneuvers in daily life combined with therapeutic exercises may be effective in relieving pain and dysfunctions in chronic low back pain patients.

Development of Water Meters for Frozen Inflation Pressure Absorption Based on Structural Analysis (구조해석 기반 동결팽창압 흡수용 수도미터 개발)

  • Kim, Kuk-il;An, Sang-byung;Lee, Byung-sun;Hong, Sung-taek
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2022.05a
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    • pp.314-316
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    • 2022
  • Instrumentation device to the amount of water used by the user is a water meter by measuring management stability is necessary. But with the onset of winter to meter water was ice inside the phase change and about 9 % and increase the volume of the meter is damaged. The existing protection bleed water meter freeze protection technology into three great bootong, supplying the heat insulation inside the external protection, water metering for water meter in the freeze protection will be divided into installing the device. Not see how far the structure for the commercialization of new technology-based products and aims to develop technologies that do not require an external power supply. Thus, freeze more vulnerable by internal pressure of the interpretation applied to a water meter in temperatures below zero internal pressure to confirm the area of preventing damage and freeze protection that can reduce the effect is superior to develop a water meter.

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A Numerical Analysis of Molten Steel Flow Under Applied Magnetic Fields in Continuous Casting

  • Yoon, Teuk-Myo;Kim, Chang-Nyung
    • Journal of Mechanical Science and Technology
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    • v.17 no.12
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    • pp.2010-2018
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    • 2003
  • Although continuous casting process has highly developed, there still remain many problems to be considered. Specifically, two vortex flows resulting from impingement against narrow walls make a flow field unstable in a mold, and it is directly related to internal and external defects of steel products. To cope with this instability, EMBR (Electromagnetic Brake Ruler) technique has been lately studied for the stability of molten steel flow, and it is revealed that molten steel flow in a mold can be controlled with applied magnetic field. However, it is still difficult to clarify flow pattern in an EMBR caster due to complex correlations among variables such as geometric factors, casting conditions, and the place and the intensity of charged magnetic field. In the present study, flow field in a mold is focused with different conditions of electromagnetic effect. To accurately analyze the case, three dimensional low Reynolds turbulent model and appropriate boundary conditions are chosen. To evaluate the electromagnetic effect in molten steel flow, dimensionless numbers are employed. The results show that the location and the intensity of the applied magnetic field significantly influence the flow pattern. Both impingement and internal flow pattern are changed remarkably with the change of the location of applied magnetic field. It turns out that an insufficient magnetic force yields adverse effect like channeling, and rather lowers the quality of steel product.