• 제목/요약/키워드: residual time

검색결과 2,085건 처리시간 0.028초

An Analytic Method for the Residual Strength Evaluation of Fire-Damaged Reinforced Concrete Beam

  • Park, Won-jun;Park, Ki-bong;Lee, Han-seung
    • Architectural research
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    • 제10권2호
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    • pp.37-42
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    • 2008
  • This study is to get the proper evaluation of the residual property of reinforced concrete beam exposed to fire. This study focused on the strength resistance and analytical evaluation of RC members exposed high temperature. And this study is the basis analytical research to conduct the other studies. To analysis by the finite element method, the Total-RC program was used to analysis it and the Total-Temp program was also used to analysis the temperature distributions at the section. All of results were compared with the pre-existing experimental data of simple supported beam. Using it, the parameters influencing the structural capacity of the high temperature-damaged RC members and residual strength estimation are investigated. The temperature distribution and the structural capacity at the section are calculated in this step. An application of this method is compared with the heating test result and residual property test for simple supported beam which is subjected to ISO 834 test fire. The results of this study are as follows; 1) The loads-displacement relationship of RC beam, considering initial thermal stress of cross section and heat transfer analysis are estimated comparing analytical value with pre-existing experimental results. 2) by the heating time (0, 1, 2 hours), the results of analysis with parameters show that the load capacity exposing at fire is affected.

The Epoxy-metal Interphase and Its Incidence on Practical Adhesion

  • Roche, Alain Andre;Aufray, Maelenn
    • 접착 및 계면
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    • 제4권2호
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    • pp.1-9
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    • 2003
  • Epoxy-amine liquid prepolymers are extensively applied onto metallic substrates and cured to obtain painted materials or bonded joint structures. Overall performances of such systems depend on the created interphase between the organic layer and the substrate. When epoxy-amine liquid mixtures are applied onto more or less hydrated metallic oxide layer, concomitant amine chemical sorption and hydroxide dissolution appear lending to the chelate formation. As soon as the chelate concentration is higher than the solubility product, these species crystallize as sharp needles. Moreover, intrinsic and thermal residual stresses are developed within painted or bonded systems. When residual stresses are higher than the organic layer/substrate adhesion, buckling, blistering, debonding may occur leading to a catastrophic drop of system performances. Practical adhesion can be evaluated with either ultimate parameters (Fmax or Dmax) or the critical strain energy release rate, using the three point flexure test (ISO 14679-1997). We observe that, for the same system, the ultimate load decreases while residual stresses increase when the liquid/solid time increases. Ultimate loads and residual stresses depend on the metallic surface treatment. For these systems, the critical strain energy release rate which takes into account the residual stress profile and the Young's modulus gradient remains quite constant whatever the metallic surface treatment was. These variations will be discussed and correlate to the formation mechanisms of the interphase.

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Traffic-load-induced dynamic stress accumulation in subgrade and subsoil using small scale model tests

  • Tang, Lian Sheng;Chen, Hao Kun;Sun, Yin Lei;Zhang, Qing Hua;Liao, Hua Rong
    • Geomechanics and Engineering
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    • 제16권2호
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    • pp.113-124
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    • 2018
  • Under repeated loading, the residual stresses within the subgrade and subsoil can accelerate the deformation of the road structures. In this paper, a series of laboratory cyclic loading model tests and small-scale model tests were conducted to investigate the dynamic stress response within soils under different loading conditions. The experimental results showed that a dynamic stress accumulation effect occurred if the soil showed cumulative deformation: (1) the residual stress increased and accumulated with an increasing number of loading cycles, and (2) the residual stress was superimposed on the stress response of the subsequent loading cycles, inducing a greater peak stress response. There are two conditions that must be met for the dynamic stress accumulation effect to occur. A threshold state exists only if the external load exceeds the cyclic threshold stress. Then, the stress accumulation effect occurs. A higher loading frequency results in a higher rate of increase for the residual stress. In addition to the superposition of the increasing residual stress, soil densification might contribute to the increasing peak stress during cyclic loading. An increase in soil stiffness and a decrease in dissipative energy induce a greater stress transmission within the material.

동영상 교육 프로그램이 자궁적출술 환자의 잔뇨량, 가스배출 및 상태불안에 미치는 효과 (The Effects of the Video Education Program on the Residual urine, Gas Passing and State Anxiety of Hysterectomy Patients)

  • 강경숙;전은미
    • 여성건강간호학회지
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    • 제16권4호
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    • pp.409-418
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    • 2010
  • Purpose: The purpose of this study was to identify the effects of a pre-operation video assisted education program on residual urine, gas passing and state anxiety in women undergoing hysterectomy. Methods: Nonequivalent control group non-synchronized design was used for the study. In the research, video assisted education program was applied to the experimental group while a similar conventional education was done to the control group. The pre-operation state anxiety and post-operation residual urine and gas discharge of both the groups were measured. The data were analyzed using SPSS. Results: The experimental group was significantly higher than control group on gas passing (t=3.04, p=.00). However the residual urine (t=0.34, p=.73) and state anxiety (t=0.81, p=.82) did not make significant differences. Conclusion: This study is very meaningful in that it developed and provided a nursing intervention can positively affect hysterectomy patients. The pre-operation video assisted education program may be an effective nursing intervention that is clinically practical and useful to reduce time of the gas passing of hysterectomy patients after the operation.

함수관측자를 이용한 장치고장검출 기법 (An Instrument Fault Detection Scheme using Function Observers)

  • 이상문;이기상
    • 대한전기학회논문지:시스템및제어부문D
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    • 제55권3호
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    • pp.91-97
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    • 2006
  • A major difficulty with the practical application of the multiple observer based IFDI schemes is the computational burden of the residual generation. In this paper, a new residual generator that employs function observers is proposed to reduce the computational burden, and the design methods of the IFDIS, equipped with the residual generator, are presented. The function observers employed in the residual generator can be considered as a dual of the unknown input (function) observer And it can be designed to estimate the measurement errors that are due to sensor faults. The error estimates are further processed to generate the residuals by which reliable fault detection/isolation result car be obtained. The proposed scheme is more useful, in real-time application, than any other multiple state observer based IFDISs. It can be effectively applied to fault tolerant control because the failure effects can be compensated by the use of the estimates of measurement errors. The proposed IFDI scheme is applied to an inverted pendulum control system for the IFDI of failed sensor and fault compensation.

항균성분의 지속력에 대한 인체적용 시험 평가 (Clinical Evaluation of Residual Effectiveness of Antibacterial Agents)

  • 최서희;김현주;이범천;문태기;김남수
    • 대한화장품학회지
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    • 제39권2호
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    • pp.133-140
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    • 2013
  • 항균비누에 흔히 사용되는 항균성분인 PCMX와 IPMP에 대하여 ASTM E2752-10 (Standard Guide for Evaluation of Residual Effectiveness of Anti- bacterial Personal Cleansing Products)에 기술된 cup scrub method에 따라 항균 지속력을 평가하였다. 건강한 남녀 총 80명의 피험자를 대상으로 한 실험에서 5% PCMX와 0.1% IPMP를 함유한 액체비누는 대조군에 비해서 E. coli와 S. aureus의 수를 통계학적으로 유의하게 감소시켰으며 27시간 동안 항균효과가 지속되는 것을 확인하였다. 항균성분의 지속력에 대한 인체적용 시험은 국내에서는 처음 시행된 것으로 결과와 함께 보고하는 바이다.

원심펌프 계통의 고장검출진단시스템 : 등가관계 접근법 (Fault Detection and lsolation System for centrifugal-Pump Systems: Parity Relation Approach)

  • 박태건;이기상
    • 대한전기학회논문지:전력기술부문A
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    • 제48권1호
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    • pp.52-60
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    • 1999
  • This paper deals with a fault detection and isolation scheme for a DC motor driven centrifugal pump system. The emphasis is placed on the design and implementation of the residual generatorm, based on parity relation, that provides decision logic unit with residuals that will be further processed to detect and isolate three important faults in the system;brush fault, impeller fault, and the speed sensor fault. Two process faults are modelled as multiplicative type faults, while the sensor fault as an additive one. With multiplicative fault, the implementation of the residual generator needs the time varying transformation matrix that must be computed on-line. Typical implementation methods lack in generality because only a numerical approximation around the assumed fault levels is employed. In this paper, a new implementation method using well tranined neural network is proposed to improve the generality of the residual generator. Application results show that the fault detection and isolation scheme with the proposed residual generator effectively isolates three major faults in the centrifugal pump system even with a wide range of fault magnitude.

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What are the most important prognostic factors in patients with residual rectal cancer after preoperative chemoradiotherapy?

  • Kim, Sol-Min;Yoon, Ghilsuk;Seo, An Na
    • Journal of Yeungnam Medical Science
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    • 제36권2호
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    • pp.124-135
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    • 2019
  • Background: We aimed to establish robust histoprognostic predictors on residual rectal cancer after preoperative chemoradiotherapy (CRT). Methods: Analyzing known histoprognostic factors in 146 patients with residual disease allows associations with patient outcome to be evaluated. Results: The median follow-up time was 77.8 months, during which 59 patients (40.4%) experienced recurrence and 41 (28.1%) died of rectal cancer. On univariate analysis, residual tumor size, ypT category, ypN category, ypTNM stage, downstage, tumor regression grade, lymphatic invasion, perineural invasion, venous invasion, and circumferential resection margin (CRM) were significantly associated with recurrence free survival (RFS) or/and cancer-specific survival (CSS) (all p<0.005). On multivariate analysis, higher ypTNM stage and CRM positivity were identified as independent prognostic factors for RFS (ypTNM stage, p=0.024; CRM positivity, p<0.001) and CSS (p=0.022, p=0.017, respectively). Furthermore, CRM positivity was an independent predictor of reduced RFS and CSS, irrespective of subgrouping according to downstage (non-downstage, p<0.001 and p<0.001; downstage, p=0.002 and p=0.002) or lymph node metastasis (non-metastasis, p<0.001 and p=0.001; metastasis, p<0.001 and p<0.001). Conclusion: CRM status may be as powerful as ypTNM stage as a prognostic indicator for patient outcome in patients with residual rectal cancer after preoperative CRT.

퇴적 환경에 따른 루미네선스 신호의 특성 (Characteristics of Luminescence Signals According to the Depositional Environment)

  • 홍성찬;최광희
    • 한국지형학회지
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    • 제28권2호
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    • pp.59-70
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    • 2021
  • This study aims to determine the sunlight exposure according to depositional environment to improve the accuracy of optically simulated luminescence (OSL) dating. Sufficient sunlight exposure during transportation of sediment is a basic assumption of the OSL dating, and if the process does not occur enough, the results may be overestimated compared to the actual depositional age. Therefore, the main purpose of this study is to establish a correction method by determining residual or unbleachable dose after sunlight exposure in the actual deposition process, not in the laboratory measurement. Four samples from two sites were collected according to the depositional environment from rivers and coasts, and various OSL signals, including the size of residual dose, degree of dispersion between grains, and OSL signal sensitivity, were measured. As a result, it was confirmed that sediments formed under temporarily high energy environments, such as floods and surges, had relatively high residual dose or large dispersion of residual dose between particles. In further studies, the OSL signal characteristics of river sediments by flow velocity will be identified and the relationship between energy and OSL signal characteristics will be identified in more detail. Moreover, a method of reconstructing the paleo-environment at the time of deposition for existing sediments will be devised. It is expected to provide important information for the frequency of disaster recurrence and prediction of future climate change.

잔여 밀집 및 채널 집중 기법을 갖는 재귀적 경량 네트워크 기반의 단일 이미지 초해상도 기법 (Single Image Super Resolution Based on Residual Dense Channel Attention Block-RecursiveSRNet)

  • 우희조;심지우;김응태
    • 방송공학회논문지
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    • 제26권4호
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    • pp.429-440
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    • 2021
  • 최근 심층 합성 곱 신경망 학습의 발전에 따라 단일 이미지 초해상도에 적용되는 심층 학습 기법들은 좋은 성과를 보여주고 있다. 현존하는 딥러닝 기반 초해상도 기법들 중 하나로 잔여 밀집 블록을 이용하여 초기의 특징 정보를 마지막 계층에 전달하여 이후의 계층들이 이전의 계층들의 입력정보를 사용하여 복원하는 RDN(Residual Dense Network)이 있다. 하지만 계층적인 모든 특징을 연결하여 학습하고 다수의 잔여 밀집 블록을 쌓게 되면 좋은 성능에도 불구하고 많은 파라미터의 수와 연산량을 가지게 되어 느린 처리 속도와 네트워크를 학습하는데 많은 시간이 소요되고 모바일 시스템에 적용이 어렵다는 단점을 가지고 있다. 본 논문에서는 이전의 정보를 다시 사용하는 연속 메모리 구조인 잔여 밀집 구조와 이미지의 특징맵에 따라 중요도를 결정해주는 채널 집중 기법을 이용한 잔여밀집 채널 집중 블록을 재귀적인 방식으로 사용하여 추가적인 파라미터 없이 네트워크의 깊이를 늘려 큰 수용 영역을 얻으며 동시에 간결한 모델을 유지할 수 있는 방식을 제안한다. 실험 결과 제안하는 네트워크는 RDN과 비교 하였을 때 4배 확대 배율에서 평균적으로 PSNR 0.205dB만큼 낮지만 약 1.8배 더 빠른 처리속도, 약 10배 더 적은 파라미터의 수와 약 1.74배 더 적은 연산량을 갖는 것을 실험을 통해 확인하였다.