• 제목/요약/키워드: Stability assessment

검색결과 974건 처리시간 0.029초

Subjective Imaging Effect Assessment for Intelligent Imaging Terminal Design: a Method for Engineering Site

  • Liu, Haoting;Lv, Ming;Yu, Weiqun;Guo, Zhenhui;Li, Xin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제14권3호
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    • pp.1043-1064
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    • 2020
  • A kind of Subjective Imaging Effect Assessment (SIEA) method and its applications on intelligent imaging terminal design in engineering site are presented. First, some visual assessment indices are used to characterize the imaging effect: the image brightness, the image brightness uniformity, the color image contrast, the image edge blur, the image color difference, the image saturation, the image noise, and the integrated imaging effect index. A linear weighted function is employed to carry out the SIEA computation and the Analytic Hierarchy Process (AHP) technique is used to estimate its weights. Second, a SIEA software is developed. It can play images after the settings of assessment index or assessment reaction time, etc. Third, two cases are used to illustrate the application effects of proposed method: the image enhancement system design for surveillance camera and the imaging environment perception system design for intelligent lighting terminal. A Prior Sequential Stimulus (PSS) experiment is proposed to improve the evaluation stability of SIEA method. Many experiment results have shown the proposed method can realize a stable system design or parameters setting for the intelligent imaging terminal in engineering site.

하천정비에 의한 하천의 물리적 교란 평가 - 남강과 영천강을 대상으로 - (Assessment of Physical Stream Disturbances by River Improvement - Case Studies of Nam River and Youngcheon River -)

  • 김기흥
    • 한국환경복원기술학회지
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    • 제12권3호
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    • pp.83-97
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    • 2009
  • The objects of study is to propose criteria for physical river disturbance assessment and as case study to show the application results for river improvement. For this purpose, the river disturbance assessment method for past disturbance process and the present-day potential natural state of stream is proposed. To assess the disturbance of the Youngcheon River caused by river improvement, One ares of Nam River was selected for the reference reach and two areas of Youngcheon River were selected for the comparison reach. And these reaches were surveyed and analyzed according to applying criteria of the river disturbances assessment. The assessment indices were physical factors as like epifaunal (bottom), embededness, velocity/depth regime, sediment deposition, channel flow status, channel alteration, frequency of riffles, bank stability, vegetative protection and riparian zone etc. The results showed that physical river environment in Youngcheon River area was disturbed by artificial revetment and bed excavation, consequently this disturbance give rise to impact of ecosystem in river. Hereafter, the criteria for river disturbance assessment are needed to consider various river characters as bed materials and bed slop etc.

Assessment of rock slope stability by slope mass rating (SMR): A case study for the gas flare site in Assalouyeh, South of Iran

  • Azarafza, Mohammad;Akgun, Haluk;Asghari-Kaljahi, Ebrahim
    • Geomechanics and Engineering
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    • 제13권4호
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    • pp.571-584
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    • 2017
  • Slope mass rating (SMR) is commonly used for the geomechanical classification of rock masses in an attempt to evaluate the stability of slopes. SMR is calculated from the $RMR_{89-basic}$ (basic rock mass rating) and from the characteristic features of discontinuities, and may be applied to slope stability analysis as well as to slope support recommendations. This study attempts to utilize the SMR classification system for slope stability analysis and to investigate the engineering geological conditions of the slopes and the slope stability analysis of the Gas Flare site in phases 6, 7 and 8 of the South Pars Gas Complex in Assalouyeh, south of Iran. After studying a total of twelve slopes, the results of the SMR classification system indicated that three slope failure modes, namely, wedge, plane and mass failure were possible along the slopes. In addition, the stability analyses conducted by a number of computer programs indicated that three of the slopes were stable, three of the slopes were unstable and the remaining six slopes were categorized as 'needs attention'classes.

치료적 승마가 뇌성마비의 체간 고유수용성, 안정성 및 자세에 미치는 영향 (The Effects of Hippotherapy over 8 Weeks on Trunk Proprioception, Stability and Posture in Cerebral Palsy Patients)

  • 정진화;유재호
    • The Journal of Korean Physical Therapy
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    • 제22권5호
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    • pp.63-70
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    • 2010
  • Purpose: In this study, children with cerebral palsy were treated for 8 weeks using horse riding trunk proprioception, stability and posture to investigate the effect of hippotherapy in the field of physical therapy. Methods: A total of 18 subjects were divided into an experimental group treated by horseback riding and a control group. Both groups were evaluated pre- and post-treatment. Trunk proprioception was measured three times in the sitting position with their eyes and ears closed to reach the target position the angle error of the mean was calculated. Trunk stability was measured using a forceplate and the data were used to calculate the postural sway path & postural sway velocity. Posture was evaluated using the Posture Assessment Scale (PAS). Results: After hippotherapy, the experimental group showed a significant improvement in trunk proprioception, stability and posture (p<0.05), but the control group improved in posture only (p<0.05). Trunk proprioception, stability and posture was significantly different between the two groups (p<0.05). Conclusion: Eight weeks of hippotherapy is effective in improving trunk proprioception, stability, and posture. Research using this therapy should be studied further as a possible new therapeutic approach in the field of physical therapy.

과도 안정도를 고려한 총 송전용량 평가 (Assessment of Total Transfer Capability Considering Transient Stability)

  • 박진욱;배인수;김진오;김규호
    • 조명전기설비학회논문지
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    • 제19권7호
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    • pp.94-99
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    • 2005
  • 본 논문은 기존의 총 송전용량 결정에 있어서 고려하기 어려웠던 과도 안정도 제약을 판별법을 적용하기 위해 2단계 계산 기법을 이용하여 보다 용이하게 적용하였다. 총 송전용량을 계산하기 위한 방법으로 첫 번째 단계에서는 RPF(Repeated Power Flow) 방법을 이용하여 전압과 열적한계를 판별하고, 두 번째 단계에서는 첫 번째 단계에서 결정된 총 송전용량이 시스템의 과도 안정도 조건의 위반여부를 판별하여 시스템의 총 송전용량을 결정하였다.

역해석기법을 통한 NATM 터널의 안정성 평가 (Stability Estimation of NATM Tunnel due to Excavation using Back Analysis)

  • 이재호;김영수;김광일;박진규;박시현;최칠용
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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    • pp.494-504
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    • 2008
  • Successful design, construction and maintenance of NATM tunnel demands prediction, control, stability estimation and monitoring of surface settlement, gradient and ground displacement with high accuracy. Back analysis using measured data and forward analysis have been and are indispensable tools to achieve this goal. Sakurai provided the hazard warning levels for assessing the stability of tunnels using the relation of critical strain and apparent Young's modulus. This paper performed the estimation of tunnel stability on construction. Firstly, the apparent Young's modulus concept and back analysis method is introduced for the assessment of tunnel safety during excavation a brief framework. Secondly, this paper deals with case study using "Apparent Young's modulus" and "Back analysis" for the purpose of estimating the stability of NATM tunnel in Korea. Finally, a general method that can be estimated the tunnel stability discussed by a flow chart.

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에너지함수를 이용한 실계통에의 과도 안정도 평가 적용 (Transient Stability assessment in the real power system using Energy Function.)

  • 권태원;이경재;이병하;함완균
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1992년도 하계학술대회 논문집 A
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    • pp.153-156
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    • 1992
  • Transient stability analysis of Korea Electric power Corporation(KEPCO) system is conducted by time simulation method, and the method is robust and reliable. But, time simulation consumes enormous computing resources and engineering time, and it does not provide a measure of the degree of stability of the system. Therefore, this method does not apply to every changed condition appropriately and quickly in planning and operating. And Transient Energy Function (TEF) method whis can assess quickly and quantatively the degree of stability of the system and which judges the stability and the instability to analyse transient dynamic charater of the system by mutual changing kinetic energy and potential energy, is developed. TEF method analyses the first Swing transient stability of the system by using the thought that if after disturbance happening, the increase of all the rotator kinetic energy changes into the potential energy after diturbance clearing, the system is stable, otherwise the system is unstable. This paper represents the availabiIity of the TEF method by comparing with time simulation method on the two cases.

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원격탐사와 지구정보시스템을 이용한 충주지역의 사면안정분석 (Analysis of Slope Stability by Using Remote Sensing and GIS Around Chungju Area)

  • 신현준;이영훈;민경덕;원중선;김윤종
    • 자원환경지질
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    • 제29권5호
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    • pp.615-622
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    • 1996
  • Slope stability analysis was conducted using remote sensing and Geoscientific Information System (GIS) as a part of natural hazard assessment around Chungju area. Landsat TM band 5 and 7 which contain more information about geological structure and geography are chosen and processed to analyse regional geological structure. Through image processing technique such as PCA, HFF, edge detection and enhancement, regional lineament can be mapped and identified. The lineament density map is constructed based on summed length of lineaments per unit area and the study area can be divided into 7 structural domains. Various factors of slope stability analysis such as geology, slope aspect, degree of slope, landcover, water shed as well as characterized structural domain are constructed as a database of GIS. Rating and weighting of each factor for slope stability analysis is decided by considering environmental geological characteristics of study area. Spatial analysis of regional slope stability is examined through overlaying technique of the GIS. The result of areal distribution of slope stability shows that the most unstable area is all over Jaeogae-ni, Hyangsan-ni and Mt. Daedun.

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이중나사산 임플란트의 안정성에 대한 평가 - 골유착 기간 중의 임상적 평가; PART II (Evaluation of Stability of Double Threaded Implant - Clinical Assessment During Osseointegration; Part II)

  • 허진호;김시엽;이주연;정창모;김용덕
    • 구강회복응용과학지
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    • 제23권4호
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    • pp.337-358
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    • 2007
  • Purpose This study was performed to evaluate the stability of dual thread implant using resonance frequency analysis in human. Materials and methods Fifty-five patients(32 males and 23 females) with a mean age of 50 years and 1 month who were treated during March, 2005 to July, 2007 in Pusan National University hospital. Totally 145 dual thread Implants were installed and initial stability was measured by Osstell $Mentor^{TM}$. After 3-6 Months, secondary stability was measured at the time of second surgery or before prosthetic treatment. Results At the time of 1st surgery, average ISQ value was $75.12{\pm}12.06$. Only 1 implant was failed during the healing period. Before prosthetic treatment, ISQ values were measured and its mean value was $80.94{\pm}6.12$. Conclusion These results suggest that the increased stability of the implant verifies the clinical relevance of double thread implant.

Analysis of pile group behaviour to adjacent tunnelling considering ground reinforcement conditions with assessment of stability of superstructures

  • Young-Jin Jeon;Cheol-Ju Lee
    • Geomechanics and Engineering
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    • 제33권5호
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    • pp.463-475
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    • 2023
  • Tunnel construction activity, conducted mainly in mountains and within urban centres, causes soil settlement, thus requiring the relevant management of slopes and structures as well as evaluations of risk and stability. Accordingly, in this study we performed a three-dimensional finite element analysis to examine the behaviour of piles and pile cap stability when a tunnel passes near the bottom of the foundation of a pile group connected by a pile cap. We examined the results via numerical analysis considering different conditions for reinforcement of the ground between the tunnel and the pile foundation. The numerical analysis assessed the angular distortion of the pile cap, pile settlement, axial force, shear stress, relative displacement, and volume loss due to tunnel excavation, and pile cap stability was evaluated based on Son and Cording's evaluation criterion for damage to adjacent structures. The pile located closest to the tunnel under the condition of no ground reinforcement exhibited pile head settlement approximately 70% greater than that of the pile located farthest from the tunnel under the condition of greatest ground reinforcement. Additionally, pile head settlement was greatest when the largest volume loss occurred, being approximately 18% greater than pile head settlement under the condition having the smallest volume loss. This paper closely examines the main factors influencing the behaviour of a pile group connected by a pile cap for three ground reinforcement conditions and presents an evaluation of pile cap stability.