• Title/Summary/Keyword: Failure grade

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Behavior of Bond-type Shallow Anchors in Rock Masses ( I ) - Metamorphic Rock (gneiss) at Taean Test Site - (암반에 근입된 부착형 앵커의 거동특성 (I) - 태안지역 편마암 -)

  • Kim, Dae-Hong;Lee, Dae-Soo;Chun, Byung-Sik;Kim, Byung-Hong
    • Journal of the Korean Geotechnical Society
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    • v.22 no.12
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    • pp.45-55
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    • 2006
  • This paper presents the results of full-scale uplift load tests performed on 30 passive anchors grouted to various lengths at Taean site in Korea. Various rock types were tested, ranging from highly weathered to sound gneiss. Rock anchors were installed over a wide range of rock types and qualities with a fixed anchored depth of $1{\sim}4m$. The majority of installations used SD4O-D51 no high grade steel rebar to induce rock failure prior to rod failure. In many tests, rock failure was reached and the ultimate loads were recorded along with observations of the shape and extent of the failure surface. The test results, the failure mechanisms as well as uplift capacities of rock anchors depend mostly on rock type and quality, embedded fixed length, and the strength of rebar. Based on test results, the main parameters governing the uplift capacity of the rock anchor system were determined.

Uplift Capacity Estimation of Bond-type Rock Anchors Based on Full Scale Field Tests (실규모 현장시험을 통한 부착형 암반앵커의 인발저항력 평가)

  • Kim, Dae-Hong;Oh, Gi-Dae
    • Journal of the Korean Geotechnical Society
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    • v.25 no.10
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    • pp.5-15
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    • 2009
  • This paper presents the results of full-scale uplift load tests performed on 24 passive anchors grouted to various lengths at Okchun and Changnyong site. Rock anchors were installed over a wide range of rock types and qualities with a fixed anchored depth of 1~6 m. The majority of installations used D51 mm high grade steel rebar to induce rock failure prior to rod failure. However, a few installations included the use of D32 mm rebar at relatively deeper anchored depth so as to induce rod failure. In many tests, rock failure was reached and the ultimate loads were recorded along with observations of the shape and extent of the failure surface. In addition to field tests, laboratory pullout tests were conducted to determine bond strength and bond stress-shear slip relation at the tendon/grout interface when a corrosion protection sheath is installed in the cement-based grout. The test results show that the ultimate tendon-grout bond strength is measured from 18~25% of unconfined compressive strength of grout. One of the important results from these tests is that the measured strains along the corrosion protection sheath were so small that practically the reduction of bond strength by the presence of sheath would be negligible.

Clinical Study of Dysphagia in Stroke Patients (1) (Preliminary paper) (뇌졸중환자의 연하장애에 관한 임상적 연구 (1))

  • Ko, Seong-Gyu
    • The Journal of Internal Korean Medicine
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    • v.18 no.1
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    • pp.62-68
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    • 1997
  • Dysphagia generally has a good prognosis after stroke involving cerebral hemisphere or braibstem, but it could have serious consquence with dehydration leading to haemoconcentration, renal failure and aspiration leading to pneumonia. This preliminary report was written for main report. The main report will be written to give an objective guide post of management and treatment in stroke patient with dysphagia. The objective guide posts were follows as, 1. Close examination for relationship between dysphagia in stroke patients and other neurological deficits 2. Influence on the prognosis of dysphagia in stroke patients by the grade of dysphagia at admission time. 3. The realtionship between the site and size of brain damage and the grade and prognosis of dysphagia 4. The frequency and prognosis of dysphagia in stroke patients according to sex and age. 5. The rate and speed of recovery with dysphagia after stroke. 6. Frequency and process of complications, aspiration pneumonia, weight loss, sore, in stroke patient group with dysphagia.

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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.

Suggestions for a better HACCP system assessment in livestock product processing plants (축산물가공장 HACCP system 평가방법 개선방안)

  • Hong, Chong-Hae;Lee, Sung-Mo
    • Korean Journal of Veterinary Service
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    • v.34 no.4
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    • pp.441-448
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    • 2011
  • According to the Korean government policy of expanding HACCP system application to food chain from farm to meat market, the importance of HACCP assessment to keep balance among the certified HACCP plants is urged. The objective of this study is to recommend more effective HACCP assessment methods. We reviewed major foreign countries HACCP implementation policy focused on the audit system, and compared with the Korean HACCP assessment system. We found that the checklist guidelines of prerequisite program were not enough for precise evaluation and many of the items were not directly related to the risk occurrences. And current rating grade for each items and judgments were inadequate to induce non-compliances and corrections for better HACCP implementation. We suggest revision points as follows; (1) checklists should be revised and reorganized according to the possibility of risk occurrences, (2) all the items should be supported by detailed guidelines for more objective inspection, (3) non-compliances identified must be reconfirmed after correction, (4) the items for HACCP plan should be divided into an accreditation inspection and a regular inspection, (5) rating grade 'high', 'medium', 'low', 'failure' was better for indicating non-compliances.

Experimental and analytical study on flexural behaviour of fly ash and paper sludge ash based geopolymer concrete

  • Senthamilselvi, P.;Palanisamy, T.
    • Computers and Concrete
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    • v.21 no.2
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    • pp.157-166
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    • 2018
  • This article presents the flexural behaviour of reinforced fly ash (FA)-based geopolymer concrete (GPC) beams with partial replacement of FA for about 10% by weight with paper sludge ash (PSA). The beams were made of M35 grade concrete and cured under three curing conditions for comparison viz., ambient curing, external exposure curing, and oven curing at $60^{\circ}C$. The beams were experimentally tested at the 28th day of casting after curing by conducting two-point loading flexural test. Performance aspects such as load carrying capacity, first crack load, load-deflection and moment-curvature behaviours of both types of beams were experimentally studied and their results were compared under different curing conditions. To verify the response of reinforced GPC beams numerically, an ANSYS 13.0 finite element program was also used. The result shows that there is a good agreement between computer model failure behaviour with the experimental failure behaviour.

Evaluation of Sample Quality for Marine Clay by Large Block Samples (대형블럭시료를 이용한 해성점토 시료의 품질 평가)

  • Kim, Jong-Kook;Yoon, Won-Sub;Kim, Ji-Hee;Chae, Young-Soo
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.1004-1011
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    • 2008
  • In this study, obtained large block sample and piston sample of marine clay in korea were performed unconfined compression and consolidation test. Soil properties of two type samples such as failure strain, between two parameter's ratio($E_{50}$ and $q_u$), and volumetric strain were used to evaluate sample disturbance. The result, large block samples show a low disturbance than piston samples. Therefore, we suggest new sample disturbance evaluated method through the relation of OCR and volumaric strain at shallow of marine clay in Korea and suggest new sample disturbance classified method by subdivided grade for failure strain of unconfined compression test.

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Service System Design Using Fuzzy Service FMEA (퍼지 서비스 FMEA를 이용한 서비스 시스템 설계)

  • Kim, Jun-Hong;Yoo, Jung-Sang
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.31 no.4
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    • pp.162-167
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    • 2008
  • FMEA (failure mode and effect analysis)is a widely used technique to assess or to improve reliability of product not only at early stage of design and development, but at the process and service phase during the product life cycle. In designing a service system, this study proposes a fuzzy service FMEA with the service blueprints as a tool which describes customer actions, onstage contact employees actions, backstage contact employees actions, support processes, and physical evidences, in order to analyse and inform service delivery system design. We fuzzified only two risk factors, occurrence and severity, to more effectively assess the potential failure modes in service. Proposed fuzzy risk grades are applied to Gaussian membership function, defuzzified into Fuzzy Inference System, and eventually identified the ranks on the potential fail points.

A Static Test of Concrete Barrier on Bridge Deck (교량 바닥판의 콘크리트 난간에 대한 정적 실험)

  • Kang, Jun-Wook;Lee, Jae-Hoon;Woo, Kwang-Sung;Ahn, Sang-Sub;Lee, Il-Gun
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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    • pp.33-36
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    • 2004
  • The current Korea bridge design specifications have no provisions about concrete Barrier. And there are no test results of registence strength of the concrete barrier at the vehicle collision sites. This paper reports experimental results of concrete barrier on bridge deck conctructed by standard drawing of SB5 grade. Eight specimens were tested under static test. The specimens are divided by two groups (D-series and B-series). D-series is to show failure pattern of bridge deck. B-series is to show failure pattern of concrete Barrier. The test results compared with calculation results using Yield-Line theory of AASHTO LRFD Bridge Design Specifications.

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A Research on the Necessity of Online Chapel Courses in Korea

  • Nam, Sang-Zo
    • International Journal of Contents
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    • v.13 no.4
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    • pp.29-38
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    • 2017
  • The objective of this study was to determine the status of current chapel courses and analyze the necessity of online chapel courses. Students' interest, failure experience, perceived problems, and advantages of current chapel courses were examined. Students' preference, intention of sincerity, and perceived effectiveness of online chapel courses were also determined. Finally, hypothesis tests for the differences of students' interest, failure experience, perceived problems and advantages of current chapel courses, preference, intention of sincerity, and perceived effectiveness of online chapel courses according to gender, school year grade, major of study, and religion were performed. Students' low interest in chapel courses was verified. Even Christian students' interest was below 3 points out of 5-point Likert scale. However, students whose religion was not Christianity felt more coercion and had less interest in chapel courses. They wanted virtualization of chapel courses more. They had more willingness to faithful participation in online chapel courses. This research suggests that virtualization of chapel courses as a solution to chapel resistance is dependent on student's characteristics such as religion, major field of study, and mindset.