• Title/Summary/Keyword: Back stress

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Application by Auto Back Tension System (오토백 인장장치의 적용성)

  • Park, Sang-Kook
    • 기술발표회
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    • s.2006
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    • pp.66-72
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    • 2006
  • The ground anchoring has been utilized over 40 years. It is growing the application of the removal ground anchor with tension force for holding earth retaining constructions in the city. It transmits tension stress of prestressed steel wire through grouting to fixed the ground that is of great advantage adjacent ground stability. Nowadays, we can find the compression dispersion anchor on many site. But, it has some problems in behavior of anchors because of impossible to tense p.c strand uniformly under the existing equipment due to different length of p c strand. Hence, motive of this research was to study the application of the newly developed tension system, that analyze and compare with the current anchoring method build on the data of in-site test and laboratory test. As a result, in case of auto back tension system, it became clear that tension pressure was equally distributed among the steal wires but the existing tension system showed sign of instability by indicating stress deflection of about 30% compare with design load. This can cause an ultimate failure of the concentrated p.c strand and a shear failure of ground.

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Surveying and Analyzing the Occupational Low Back Pains in General Hospital Nurses (종합병원 간호사의 직업성 요통 실태조사 및 요인분석)

  • 정화식;김우열;장귀남;한은경
    • Proceedings of the Safety Management and Science Conference
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    • 2000.11a
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    • pp.255-259
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    • 2000
  • Despite improved working environment with increased automation in industry, the nursing professions are subject to great deal of potential occupational risks, including chemical exposure, occupational stress, and musculoskeletal stress. In this study, we investigated the work-related Low Back Pains(LBPs) among hospital nursing profession by questionnaire survey. The results showed that over 89% of nursing personnel answered had experienced work-related LBPs. Among these personnel, patient handling caused more than 78% of the incidents occurring at work. This study will thus contribute as a basic reference to the hospitals and ergonomic practitioners for nursing profession training program development, facility and equipment redesign, and for guiding future research concerning prevention of this very important occupational health problem.

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Recycling of In-site waste soil material to fill a hollow between PHC pile and Earthen wall

  • Jang, Myung-Houn;Choi, Hee-Bok
    • Journal of the Korea Institute of Building Construction
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    • v.12 no.5
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    • pp.510-517
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    • 2012
  • This study evaluated the recycling potential of in-site waste soil as pile back filling material (PBFM). We performed experiments to check workability, segregation resistance, bond strength, direct shear stress test, and dynamic load test using in-site waste soil in coastal areas. We found that PBFM showed better performance than general cement paste in terms of workability, segregation resistance, and bond strength. On the other hand, the structural performance of PBFM was slightly lower than that of general cement paste due to the skin friction force of pile by Pile Driving Analyzer and direct shear stress. However, because this type of performance degradation in terms of structure can be improved through the use of piles with larger diameter or by changing the type of pile, considering the economics and environment, we considered that recycling of PBFM has sufficient value.

Modified Disturbed State Concept for Dynamic Behaviors of Fully Saturated Sands (포화사질토의 동적거동규명을 위한 수정 교란상태개념)

  • 최재순;김수일
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2003.09a
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    • pp.107-114
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    • 2003
  • There are many problems in the prediction of dynamic behaviors of saturated soils because undrained excess pore water pressure builds up and then the strain softening behavior is occurred simultaneously. A few analytical constitutive models based on the effective stress concept have been proposed but most models hardly predict the excess pore water pressure and strain softening behaviors correctly In this study, the disturbed state concept (DSC) model proposed by Dr, Desai was modified to predict the saturated soil behaviors under the dynamic loads. Also, back-prediction program was developed for verification of modified DSC model. Cyclic triaxial tests were carried out to determine DSC parameters and test result was compared with the result of back-prediction. Through this research, it is proved that the proposed model based on the modified disturbed state concept can predict the realistic soil dynamic characteristics such as stress degradation and strain softening behavior according to dynamic process of excess pore water pressure.

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A Case Report of the Herbal Medication Treatment and Psychotherapy for a Patient with Psychogenic Chronic Low Back Pain (심인성(心因性) 만성요통(慢性腰痛) 환자에 대해 한방치료(韓方治療)와 정신요법(精神療法)을 적용한 1례)

  • Kim, Ji-Hyung;Han, Chang;Ryu, Ki-Joon;Ahn, Keon-Sang;Kwon, Seung-Ro;Cho, Jae-Hee
    • Journal of Oriental Neuropsychiatry
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    • v.19 no.3
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    • pp.299-307
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    • 2008
  • In this study, we treated a patient with psychogenic chronic low back pain for 2 years with herbal medication treatment and psychotherapy. The case was a 17 years old female patient complained chronic low back pain for a long time. She received the spine operation, epidural injection, many kind of oriental medicine treatment about low back pain, but there was no improvement. We diagnosed her pain as a psychogenic pain disorder, and treated her with herbal medication for decrease her stress, and did a psychotherapy such as the progressive muscle relaxation, and counseled about trouble with her family. After treatment, her chronic low back pain was improved so much. We think that the herbal medication treatment and psychotherapy can be helpful to treat patients who have psychic and physical disorders.

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Effects of Yoga on Pain, Function, and Depression in Individuals with Nonspecific-Low Back Pain

  • Song, Seonghyeok;Choi, Youngam;Cho, Namjeong;Kim, Hyun-Joong
    • Physical Therapy Rehabilitation Science
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    • v.11 no.2
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    • pp.165-171
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    • 2022
  • Objective: Nonspecific low back pain (NSLBP) is experienced worldwide by many age groups. Yoga is recommended as an exercise to reduce back pain and stress because it is a breathing exercise, posture, and meditation as key elements. The aim of this study is to compare the effects of yoga and stabilization exercise on pain intensity, function, and depression. Design: An open-label, parallel arm, randomized controlled trial Methods: Twenty-four participants were allocated to the experimental and the control group in a ratio of 1:1. Yoga (experimental group) and stabilization exercise (control group) were received twice a week for 6 weeks Participants were assessed at baseline and post-intervention for pain intensity (numeric pain rating scale), function (Aberdeen low back pain scale, flexibility,and strength), and depression (Beck depression inventory). Results: When the experimental group (Yoga) and control group (stabilization exercise) were performed twice a week for 6 weeks, numeric pain rating scale, Aberdeen low back pain scale, and flexibility in post-intervention showed significant improvement in both groups (P<0.05), However, in all variables, the experimental group showed a positive benefit compared to the control group (P<0.05). Conclusions: The results of this study show that yoga has more positive benefits compared to stabilization exercise in pain intensity, function, and depression in individuals with NSLBP.

Roll의 수명예측 model 개발

  • 배용환;장삼규;이석희
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1992.04a
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    • pp.306-312
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    • 1992
  • The prevention of roll breakage in hot rolling process is improtant to reduce maintenance cost and production loss. Rolling conditions such as the roll force and torque have been intensively studied to overcome the roll breakage. in the present work, a model for life prediction of work rolls under working condition was developed and discussed. The model consists of stress analysis, crack propagation, wear and fatigue calculation model. Roll life can be predicted by stress, crack depth and fatigue damage calculated from this model. The reliability of stress analysis is backed up by the FEM analysis. From the result of simulation using by pressent model, although the fatigue damage of back up roll reachs 80% of practical limit, that of workroll was less than 40%. In edge section of workroll stress amplification is found by wear and bender effect. We can judge that workroll failures are not due to fatigue damage, crack propagation by bending stress but stress amplification by wear and bender in present working condition.

Complex Trauma and Disorder of Extreme Stress(DESNOS) (복합외상과 극단적 스트레스 장애)

  • Park, Seon-Cheol;Kim, Seok-Hyeon
    • Anxiety and mood
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    • v.5 no.2
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    • pp.80-88
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    • 2009
  • Disorder of Extreme Stress, Not Otherwise Specified (DESNOS) is the proposed diagnosis that meets the severe, complex, and prolonged psychological sequela of victims with chronic traumatization (e.g., family violence, incest, and childhood sexual or physical abuse). The hallmarks of DESNOS are a multiplicity of symptoms (e.g., somatization, dissociation, and depression), pathological changes in relationships, identity disturbances, and a propensity to experience repeated harm and injury at the hands of oneself and others. DESNOS can be directly assessed by Structured Interview of Disorder of Extreme Stress (SIDES) and Self- Report Inventory of Disorder of Extreme Stress (SIDES-SR). The treatment of DESNOS should be phaseoriented and involve movement back and forth among three basic stages : 1) stabilization ; 2) trauma processing ; 3) reintegration.

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Optimal Design of Press-Fitted Axle Shaft Considering Stress Relief (압입축의 손상저감을 위한 최적설계 연구)

  • Ko, Jaechun;Lee, Jongsoo;Choi, Ha-Young
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.22 no.5
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    • pp.859-864
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    • 2013
  • Creation of a stress relief groove is a fairly simple yet high-performance method. During the application of this method, it is important to consider the location and size of the groove in order to achieve better performance. Consequently, this research proposes an approach for optimizing the application of the stress relief groove method to a press-fitted assembly. In a boss design, the position and diameter of the groove are configured as design variables and the design of experiments is applied. Based on this information, a 3D model is built and analyzed using the finite element analysis software ABAQUS. Meta-models are created using back-propagation neural networks. Then, deterministic optimization results obtained from a genetic algorithm are compared with the results of the finite element analysis. The temperature sensitivity of the optimized model is analyzed, and finally, reliability-based design optimization is conducted for enhancing the design quality.

A Comparative Study of Material Flow Stress Modeling by Artificial Neural Networks and Statistical Methods (신경망을 이용한 HSLA 강의 고온 유동응력 예측 및 통계방법과의 비교)

  • Chun, Myung-Sik;Yi, Joon-Jeong;Jalal, B.;Lenard, J.G.
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.21 no.5
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    • pp.828-834
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    • 1997
  • The knowledge of material stress-strain behavior is an essential requirement for design and analysis of deformation processes. Empirical stress-strain relationship and constitutive equations describing material behavior during deformation are being widely used, despite suffering some drawbacks in terms of ease of development, accuracy and speed. In the present study, back-propagation neural networks are used to model and predict the flow stresses of a HSLA steel under conditions of constant strain, strain rate and temperature. The performance of the network model is comparedto those of statistical models on rate equations. Well-trained network model provides fast and accurate results, making it superior to statistical models.