• 제목/요약/키워드: External and internal stability

검색결과 277건 처리시간 0.035초

학교체육관의 구조계획을 위한 구조시스템 구성요소의 변화와 건축특성의 영향분석 (An Analysis on the Relationship of Architectural Features and Composition Elements for Structure Planning in School Gymnasium)

  • 이주나
    • 교육시설 논문지
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    • 제26권5호
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    • pp.25-36
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    • 2019
  • School gymnasium is a multi-purpose large space building for various events and physical education activities, and is a facility that requires an approach to the desirable structural design, besides mechanical problems of structure against loads. For the integrated structure design concerning the architectural features, the major considerations of gymnasium planning that are the internal and external shape of the gymnasium, the space scale with structure members, the structural efficiency by members weight reduction and openness of the gymnasium space will have to take into account in the structural planning. From this point of view, the several cases of the school gymnasium were investigated and the parametric analyses were performed to the models using the various structural system. The parameters were the composition elements of structure system that are profile of structure, rigidity of member, connection and anchorage and stability. At the result, It was presented that the profile of structure member was the most influential factor to structural efficiency and the effect of the form and space of gymnasium. Also the design informations of structure design having the various feature of form and space were presented for the initial gymnasium planning.

Core muscle Strengthening Effect During Spine Stabilization Exercise

  • Han, Kap-Soo;Nam, Hyun Do;Kim, Kyungho
    • Journal of Electrical Engineering and Technology
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    • 제10권6호
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    • pp.2413-2419
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    • 2015
  • Core spinal muscles are related to trunk stability and assume the main role of stabilizing the spine during daily activities; strengthening of core muscles around the spine can therefore reduce the chance of back pain. The objective of the study was to investigate the effect of core muscle strengthening in the spine during spine stabilization exercise using a whole body tilt device. To achieve this, a validated musculoskeletal (MS) model of the whole body was used to replicate the input motion from the whole body tilting exercise. An inverse dynamics analysis was executed to estimate spine loads and muscle forces depending on the tilting angles of the exercise device. The activation of long and superficial back muscles such as the erector spinae (iliocostalis and longissimus) were mainly affected by the forward direction (-40°) of the tilt, while the front muscles (psoas major, quadratus lumborum, and external and internal obliques) were mainly affected by the backward tilting direction (40°). Deep muscles such as the multifidi and short muscles were activated in most directions of the rotation and tilt. The backward directions of the tilt using this device could be carefully applied for the elderly and for rehabilitation patients who are expected to have less muscle strength. In this study, it was shown that the spine stabilization exercise device can provide considerable muscle exercise effect.

아동의 삶의 질에 대한 개념 분석 (A Concept Analysis of the Quality of Life for the Children)

  • 장은영;오진아
    • 부모자녀건강학회지
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    • 제11권2호
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    • pp.127-137
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    • 2008
  • Purpose: The purpose of this study was to attempt an accurate understanding of the quality of life for the children and provide basic materials for application to nursing research, intervention and further theoretical development. Method: Data obtained from such research methods as the lexical and literature review were analysed according to Walker and Avant's(1995) process of concept analysis. Results: As a result of analysis, it was found that the attributes of the concept of the quality of life for the children included value/acceptance, family relationship, safety, good relationship with friends, right of children, school life, parent relationship, leisure, economical stability, not child abuse, and health. There was the coexistence between antecedent element and the outcomes of subjective judgement - health, family, economic strength, education, friends, welfare, social-cultural environment which indicates the coexistence of positive and negative emotions. Conclusion: nursing intervention should be provided for children by concentrating focus on the coordination of internal and external situations in order to prompt them to express their life with positive emotions. Experiential reference was used to suit the purpose of this study based on the use of objective and subjective indicators, and the development of the instrument considering the children were proposed because of the absence of the unified measurement instrument.

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바이모달트램 차량인프라시스템에 관한 연구 (Study on Vehicle Infra System of Bimodal Tram)

  • 이강원;윤희택;박영곤;황의경
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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    • pp.2147-2152
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    • 2011
  • This study of bimodal integration management system in conjunction with the tram and the tram cars bimodal integrated management system that occupies a part of the system to perform its role as a bimodal tram vehicle configuration, a device for the vehicle's infrastructure ryureul development and it is aimed to build on the vehicle. Bimodal tram vehicle infrastructure systems, internal and external information of the larger vehicles, and vehicles used to collect information for its own part and the integrated operations management center, or providing partial information from the station and collect/provide for the transfer of information to the communication part consists In this study, the core of these devices, the configuration of the vehicle infrastructure systems for the overall management and control of vehicles operating a computer's central processing device, vehicle infrastructure systems that make it manages and stores all jangchiryu Integrated Operations Management Center is reporting. In addition, seamless integration with operational management center for interactive communication in a vehicle mounted communications devices to maintain the best condition to manage. Current general traffic management system in a similar terminal device being used, but bimodal tram vehicles operating the computer of the vehicle operates the infrastructure to configure the devices around the one to configure the system in terms of step enhanced the active type, the operating terminal unit of inter active type. In this study, considering the future alignment of the accounting fee system, the expansion of the system reliability and stability around the activities that are underway.

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유한요소법을 이용한 유기압 현수장치의 열전달 해석 (Heat Transfer Analysis of Hydropneumatic Suspension Unit By Finite Element Method)

  • 배징도;조진래;이홍우;송정인;이진규
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.531-536
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    • 2004
  • In-arm type hydropeumatic suspension unit(ISU) is an equipment of armed tracked vehicle to absorb impact load and vibration from the irregular ground. During the operation of ISU, main piston moves forward and backward and oil flowing through damper transmits the external impact load to floating piston. Heat is generated in ISU by the oil pressure drop through the damper orifice and the friction between cylinder wall and two pistons. On the other hand, internal heat dissipatis outside via heat convection. Occurrence of high temperature can deteriorate durability of major components and basic function of ISU. And, it can cause fatal problem in the ISU life time and the sealing performance of piston rings. As well, the spring constant change of nitrogen gas that is caused by the temperature rise exerts the negative effect to the vehicle stability. Therefore, in this paper, we analyze the heat transfer analysis of the entire ISU unit, by finite element method, with the outside flow velocities 8m/s and 10m/s.

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The Effects of Vibration Exercise after Modified Bröstrom Operation in Soccer Players with Ankle Instability

  • Kim, Sanghoon;Kim, Yangrae;Kim, Yongyoun
    • 국제물리치료학회지
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    • 제10권2호
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    • pp.1791-1796
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    • 2019
  • Background: Vibration exercise after ankle surgery improves proprioception and ankle muscle strength through vibration stimulation. Objective: To examine the effects of vibration exercise on the ankle stability. Design: Randomized controlled clinical trial (single blind) Methods: Twenty soccer players were randomly divided into experimental group and control group. The Vibration exercise program was conducted 12 weeks and 3 times a week. Ankle joint proprioceptive sensory test and Isokinetic muscle strength test were performed using Biodex system pro III to measure plantar flexion / dorsiflexion and eversion / inversion motion. Results: The result of isokinetic test of ankle joint is showed significant improvement in all measurement items, such as leg flexion, lateral flexion, external and internal muscle forces, compared to previous ones by performing vibration movements for 12 weeks. However, in the comparison group, plantar flexor ($30^{\circ}$), eversion muscle ($120^{\circ}$), inversion ($30^{\circ}$) of limb muscle strength were significantly improved compared with the previous phase; was no significant difference in dorsi-flexion. There was no significant difference between groups in all the items. Conclusions: In this study, we analyzed the effects of rehabilitation exercise on soccer players who had reconstructed with an ankle joint ligament injury through vibration exercise device. As a result, we could propose an effective exercise method to improve the ability, and confirmed the applicability as an appropriate exercise program to prevent ankle injuries and help quick return.

전단변형 및 감쇠효과를 고려한 비보존력을 받는 외팔기둥의 동적 안정성거동에 대한 매개변수연구 (Parametric Study on Dynamic Stability Behaviors of Beck's Column considering Shear Deformation and Damping Effects)

  • 이준석;김남일;김문영
    • 한국지진공학회논문집
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    • 제9권6호
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    • pp.1-12
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    • 2005
  • 비보존력(non-conservative force)을 받는 외팔기둥의 동적 안정성 거동특성을 조사하기 위하여, 전단변형 및 감쇠효과가 고려된 Hamilton의 원리를 적용하고 무차원화 된 운동방정식 및 유한요소 정식화 과정을 제시한다. 유도된 행렬운동방정식을 이용하여 외팔보(Beck's column)의 고유치해석에 의한 정적좌굴(divergence) 및 동적 좌굴하중(flutter load)을 산정하고 $Newmark-{\beta}$법에 의해서 시간응답해석을 실시한다. 이러한 해석법을 이용한 매개변수연구를 통하여 전단변형 및 회전관성효과, 비보존력의 방향파라미터에 대한 임계하중의 영향, 그리고 내적 및 외적 감쇠하중의 영향이 비보존력계의 동적 안정성에 미치는 영향을 분석한다.

Variation of Pull-out Resistance of Geogrid with Degree of Saturation of Soil

  • Yoo, Chungsik;ALI, TABISH
    • 한국지반신소재학회논문집
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    • 제19권1호
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    • pp.1-9
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    • 2020
  • This paper presents the results of experimental investigation on the effect of degree of saturation of soil on the pullout behavior of a geogrid. Different test variables were taken into account while performing the experiment including the soil physical conditions based on water content and external loading applied. The soil used was locally available weathered granite soil. The tests included variations in saturation of about 90%, 80%, 70% and 45% (optimum moisture content). The pullout tests were performed according to ASTM standard D 6706-01. The results indicate that increasing the degree of saturation in the soil decreases the pull-out capacity, which in turn decreases the interface friction angle and interaction coefficient. The decrease in the pullout interface coefficient was observed to be around 12.50% to 33.33% depending on the normal load and degree of saturation of the soil. The test results demonstrated the detrimental effect of increasing the degree of saturation within the reinforce soil on the pullout behavior of reinforcement, thus on the internal stability. The practical inferences of the outcomes are analyzed in detail.

감시정찰 전자광학장비용 스프링 안정화 장치 구조 설계 및 해석 연구 (The Structural Design and Analysis of Spring Stabilizer for Aircraft Surveillance and Reconnaissance EO/IR Equipment )

  • 정윤주;김수현;남상현;박인재;박민균;김태균;양환석;박승욱;이승하
    • 항공우주시스템공학회지
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    • 제17권5호
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    • pp.28-33
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    • 2023
  • 본 연구에서는 기존 항공기 탑재 EO/IR 장비 내부 짐벌과 방진구를 스프링으로 대체하여, 외부 진동 감쇠 효과와 6자유도 구동이 가능한 내부 플랫폼 시스템을 분석하였다. 제안한 스프링 안정화 장치는 기계제작 스프링과 스프링 모듈, 스프링 모듈-내부 플랫폼 간 연결을 위한 지지 구조물로 구성된다. 본 연구에서는 모드 해석을 통해 스프링의 재질을 선정하였으며, 랜덤 진동 해석을 통해 스프링 안정화 장치의 구조 건전성을 분석하였다.

Technologies for the Removal of Water Hardness and Scaling Prevention

  • Ahn, Min Kyung;Han, Choon
    • 에너지공학
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    • 제26권2호
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    • pp.73-79
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    • 2017
  • In nucleation assisted crystallization process formed $CO_2$ leaves as colloid gas and is used as the template by the rapidly growing crystals in the nucleation site. This emulsion of $CaCO_3$ micro-crystals & $CO_2$ micro-bubbles forms hollow particles. Formed hollow particles are double walled, both internal and external faces belonging to the cleavage aragonites which separate the surrounding water from the enclosed gas cavity. Hence, the reverse reaction of $CO_2$ with water forming Carbonic Acid is not possible and the pH stability is maintained. In fact every excess $CaCO_3$ crystals are buffering any carbonic acid left over. This $CO_2$ based nucleation technology prevents scale formation in water channels, but it also helps to reduce the previously formed scales. This process takes out water dissolved $CO_2$ in almost-visible micro-bubbles forms that helps reducing previously formed scale over a period of time (depends on the usage period). The aragonite crystals can't form scale because of its stable molecular structure and neutral surface electro potentiality.