• Title/Summary/Keyword: field failure data

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A Study on the Management Plan of Fire Protection System Utilizing Urban Spatial Information (공간정보를 활용한 소방시설의 관리방안 연구)

  • Bang, Changhoon
    • Fire Science and Engineering
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    • v.33 no.3
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    • pp.98-104
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    • 2019
  • This study examined the efficient management of a fire protection system using spatial information, and basic data for the development of related firefighting industry were obtained. To overcome the problems of malfunction and management failure, which are the major issues of fire protection system management, this study analyzed the related laws and regulations on building spatial information of a fire protection system to introduce spatial information to the fire protection system field. For efficient management of the fire protection system, it is necessary to revise the related laws of the fire protection system, such as protection system-related laws including space information technology, and maintain the standardization, effectiveness, and consistency of fire protection system spatial information.

Risk management applicable to shield TBM tunnel: II. Risk analysis methodology (쉴드 TBM 터널에 적용 가능한 리스크 관리: II. 리스크 분석 방법)

  • Hyun, Ki-Chang;Min, Sang-Yoon;Moon, Joon-Bai;Jeong, Gyeong-Hwan;Lee, In-Mo
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.14 no.6
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    • pp.683-697
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    • 2012
  • In this paper, a risk analysis methodology applicable to shield TBM tunnels was studied. Fault Tree Analysis (FTA) was utilized to identify all risk items and to calculate the probability of failure of each item and Analytic Hierarchy Process (AHP) was used to obtain the impact of each risk item. Finally, a risk level of each risk item can be assessed. Developed methodology is applied to a Seoul subway site in which EPB shield tunnel method was utilized and it was found that risk analysis results matched reasonably well with field data.

Contractors' Perception towards Safety and its Consequences on Construction Workers in Cape Coast Metropolis

  • Mustapha, Zakari
    • The Korean Journal of Food & Health Convergence
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    • v.5 no.6
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    • pp.11-16
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    • 2019
  • The construction environment has been declared as a hazard prone area due to high number of accident and death. The study aims to identify influential factors that contribute to poor safety practices and its consequences on construction workers in Cape Coast Metropolis. Seventy respondents were taken as the sample size for the study. Descriptive analysis was used to analyze the data obtained from the field. Findings show that poor site management, working without safety gadgets, failure to use their Personal Protective Equipment (PPE) and negligence of workers were the main causes of accidents on sites. Poor site management had the highest ranking among the seven variables. Effects of poor safety practices on building construction site and delays in work execution were due to injury of workers, extra cost due to payment of compensation to injured victims, not motivated due to injury of worker and declined reputation of firm. Management team should motivate workers for safe work done, provide adequate PPE for their workers on site and have documented health and safety policy on site. Site authorities and management team should be on site regularly to ensure proper safety practices on construction site.

A Field Survey on the Structure and Maintenance Status of Pipe Framed Greenhouses (파이프 골조 온실의 구조 및 유지관리실태 조사분석)

  • 남상운
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.42 no.4
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    • pp.106-114
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    • 2000
  • An investigation was conducted to get the basic data for establishing maintenance strategy of pipe framed greenhouses. The contents of the investigation consisted of actual state of structures, maintenance status, meteorological disaster, and corrosion characteristics of pipe framework in greenhouses. the number of greenhouses investigated was 108 in total. Most multi-span greenhouses had narrower width and lower height than the standared 1-2W greenhouse, and most of single-span greenhouses were tunnel type. In multi-span greenhouses, the size and interval of frameworks such as rafter, purline, column , and cross beam were mostly suitable, but frameworks of single-span greenhouses were mostly insufficient. After about 7 years in grounds, 8 years in joints, 10 years in bending parts. and 13 years in columns. pipe surface was mostly rusted. Most weak parts in corrosion were pipes in contact with the ground, joints, roll-up shaft pipes, and pipes close to the gutter. Almost all of the greenhouse farmers didn't pay any attention to maintenance affair in a regular interval for pipe framed grenhouses. Many greenhouses have experienced the meteorologicla diaster such as uplift of foundation, partial or complete failure by the hyphoon and/or high winds.

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Investigating the fatigue failure characteristics of A283 Grade C steel using magnetic flux detection

  • Arifin, A.;Jusoh, W.Z.W.;Abdullah, S.;Jamaluddin, N.;Ariffin, A.K.
    • Steel and Composite Structures
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    • v.19 no.3
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    • pp.601-614
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    • 2015
  • The Metal Magnetic Memory (MMM) method is a non-destructive testing method based on an analysis of the self-magnetic leakage field distribution on the surface of a component. It is used for determining the stress concentration zones or any irregularities on the surface or inside the components fabricated from ferrous-based materials. Thus, this paper presents the MMM signal behaviour due to the application of fatigue loading. A series of MMM data measurements were performed to obtain the magnetic leakage signal characteristics at the elastic, pre-crack and crack propagation regions that might be caused by residual stresses when cyclic loadings were applied onto the A283 Grade C steel specimens. It was found that the MMM method was able to detect the defects that occurred in the specimens. In addition, a justification of the Self Magnetic Flux Leakage patterns is discussed for demonstrating the effectiveness of this method in assessing the A283 Grade C steel under cyclic loadings.

Study on Pullout Behavior and Determination of Ultimate Uplift Capacity of Pile Driven in Small Pressured Chamber (소형 압력 토조내에 타입된 말뚝의 인발 거동과 극한 인발 지지력 결정에 관한 연구)

  • 최용규
    • Geotechnical Engineering
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    • v.11 no.2
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    • pp.19-28
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    • 1995
  • Based on the various test data acquired in the field, the large pressure chamber and the small pressure chamber, uplift behaviors and method of determining the ultimate uplift capacity of pile driven in small pressure chamber were studied. After uplift pile experienced 2 or 3 sudden slip due to increase of uplift load, complete pullout failure was occurred. Thus, it appears that the ultimate uplift capacity could be identified as the load at displacement where first slip occurs. The ultimate uplift capacity might be determined in every test and the disturbance after first uplift test could be recovered by adding one blow of the drop hammer, which had to depend on the model pile capacity.

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Numerical and experimental study on flexural behavior of reinforced concrete beams: Digital image correlation approach

  • Krishna, B. Murali;Reddy, V. Guru Prathap;Tadepalli, T.;Kumar, P. Rathish;Lahir, Yerra
    • Computers and Concrete
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    • v.24 no.6
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    • pp.561-570
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    • 2019
  • Understanding the realistic behavior of concrete up to failure under different loading conditions within the framework of damage mechanics and plasticity would lead to an enhanced design of concrete structures. In the present investigation, QR (Quick Response) code based random speckle pattern is used as a non-contact sensor, which is an innovative approach in the field of digital image correlation (DIC). A four-point bending test was performed on RC beams of size 1800 mm × 150 mm × 200 mm. Image processing was done using an open source Ncorr algorithm for the results obtained using random speckle pattern and QR code based random speckle pattern. Load-deflection curves of RC beams were plotted for the results obtained using both contact and non-contact (DIC) sensors, and further, Moment (M)-Curvature (κ) relationship of RC beams was developed. The loading curves obtained were used as input data for material model parameters in finite element analysis. In finite element method (FEM) based software, concrete damage plasticity (CDP) constitutive model is used to predict the realistic nonlinear quasi-static flexural behavior of RC beams for monotonic loading condition. The results obtained using QR code based DIC are observed to be on par with conventional results and FEM results.

The Conceptual Structure of Coping -Based on Patients receiving Hemodialysis - (대처(coping)의 개념적 구조 -혈액투석환자를 대상으로-)

  • Chang Sung-Ok;Lee Sook-Ja;Kim Jung-Sook
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.7 no.1
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    • pp.42-59
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    • 2000
  • This study was done to analyze and develop the concept of coping in patients receiving hemodialysis. The Hybrid Model of concept development was applied to develop a conceptual structure of coping in patients receiving hemodialysis, which included a field study carried out using an in-dept interview with 18 patients in the hemodialysis room of one general hospital in Seoul. Data-analysis was done in three phases as suggested by the Hybrid Model. Finally, by summarizing the results from each case, the attributes of coping, its dimensions, definition and structure were outlined. According to the results of the study, a conceptual structure of coping which centers around stressors, stress-appraisal, strategy of coping and new definitions of coping in patients receiving hemodialysis was suggested : The coping of patients receiving hemodialysis is a process that deals with physical, emotional, inter-personal, and role stress caused by hemodialysis due to renal failure. It has a series of phases which include a phase that appraises the stressful situation based on past experience of chronic disease management, one's remaining rears, the extent of family support, the extent of economic dependency, inter-personal support. education and uncertainty, and a phase of developing coping strategies that con be affected by social support and self esteem. As a result of coping, patients adapt or not to the life situation of receiving hemodialysis.

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A Study on the Reliability Performance Evaluation of Software Reliability Model Using Modified Intensity Function (변형된 강도함수를 적용한 소프트웨어 신뢰모형의 신뢰성능 비교 평가에 관한 연구)

  • Kim, Hee Cheul;Moon, Song Chul
    • Journal of Information Technology Applications and Management
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    • v.25 no.2
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    • pp.109-116
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    • 2018
  • In this study, we was compared the reliability performance of the software reliability model, which applied the Goel-Okumoto model developed using the exponential distribution, to the logarithmic function modifying the intensity function and the Rayleigh form. As a result, the log-type model is relatively smaller in the mean squared error compared to the Rayleigh model and the Goel-Okumoto model. The logarithmic model is more efficient because of the determination coefficient is relatively higher than the Goel-Okumoto model. The estimated determination coefficient of the proposed model was estimated to be more than 80% which is a useful model in the field of software reliability. Reliability has been shown to be relatively higher in the log-type model than the Rayleigh model and the Goel-Okumoto model as the mission time has elapsed. Through this study, software designer and users can identify the software failure characteristics using mean square error, decision coefficient. The confidence interval can be used as a basic guideline when applying the intensity function that reflects the characteristics of the lifetime distribution.

Effect of Anchorage Type of CFS on Flexural Behavior of RC Beams (탄소섬유쉬트의 정착 보강방법이 RC보의 휨거동에 미치는 영향)

  • Shin, Sung Woo;Bahn, Byong Youl;Lee, Kwang Soo;Cho, In Chol
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.2 no.2
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    • pp.202-208
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    • 1998
  • To investigae the effect of anchorage type of carbon fiber sheet (CFS) on flexural behavior of RC beams, the loading test of RC beams reinforced with CFS was conducted in variable of anchorage Type such as bolting anchorage and U type anchorage using CFS. This study can be summarized as follows ; It is confirmed experimentally that the bolting anchorage and U type anchorage with CFS is very effective to delay the bond failure and prevent the peeling of CFS. Also, the anchorage type applied with this study is very effective to improve the ductility compared with the improving of maximum flexural strength of RC beams. It is believed that the anchorage type used this study must secure the ductile capacity of above 3 for the flexural strengthening of RC beams. In the future, it is required to obtain the data about anchorage type of CFS for utilization of field work as well as investigate the ductile capacity of conventional study of anchorage type

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