• Title/Summary/Keyword: technical state inspection

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A Study on Pricing Criteria of the Laboratory Safety Inspection and Diagnosis (연구실 점검 및 진단 대가기준에 관한 연구)

  • Lee, Jong-Ho
    • Journal of the Korean Society of Safety
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    • v.33 no.5
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    • pp.170-176
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    • 2018
  • Laboratory inspection and diagnosis is a means of investigating and assessing various hazards or the state of research equipment in a laboratory, then taking appropriate safety measures to prevent accidents and injury. In many cases, laboratory inspection and diagnosis carried out by agencies are performed in a perfunctory manner that only barely satisfies the legal requirements. The aim of the present study is to provide clearly established pricing criteria for laboratory inspection and diagnosis, so as to prevent recurrence of laboratory accidents and to establish a safe laboratory environment. In order to clarify previously unclear matters, such as the lower limit for bids submitted by laboratory inspection and diagnosis agencies, technical manpower requirements, and number of laboratories inspected and diagnosed per day, a questionnaire survey was administered to agency personnel. First, when asked what the lower limit for bids submitted by agencies should be in order to improve reliability of inspection and diagnosis results and make up for the shortcomings of the lowest-bidder-wins system, 85.5% of respondents answered that the lower limit for bids should stand at no lower than 90% of the estimated price. The level of technical expertise among the technical personnel committed to laboratory inspection and diagnosis was shown to impact the reliability of results, and questionnaire results indicated a need to vary technical expertise levels depending on the degree of hazard, substances handled, and equipment used in a given laboratory. Level of technical expertise(67.1%) and number of personnel(52.6%) were shown to have a greater impact on reliability of diagnosis than on reliability of inspection. According to the results, it is determined that three persons(specialist, advanced and intermediate) should be committed to inspections, while four persons(professional, specialist, advanced and intermediate) should be committed to diagnoses. The respondents indicated a larger number of laboratories could be inspected than diagnosed per day. This can be attributed to differences in the amount of work each task involves, and the time each task takes. Assuming a six-hour work day not counting transportation, paperwork and rest, it is thought that inspection of up to 36 laboratories will be possible if each laboratory is assigned no more than 10 minutes(34.7%), while up to 24 laboratories could be inspected and diagnosed if each laboratory is assigned 15 to 20 minutes(35.1%).

A Study of Quality Improvement of the Exterior Inspection Using Tunnel Scanning System (터널스캐닝 시스템을 이용한 외관조사 품질개선에 관한 연구)

  • Jee Kee-Hwan;Chung Jae-Min;Hong Sa-Jang;Kim Su-Un
    • Proceedings of the KSR Conference
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    • 2004.10a
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    • pp.234-239
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    • 2004
  • Recently, the tunnel structures are increasing. And the tunnels are to be large diameter tunnel and long. Therefore, inspection, repair, and maintenance of tunnels are an extremely important part of infrastructure management, with particular technical and safety considerations arising from the very nature of underground construction. To inspect surface state of tunnels, concrete structures, it must generally use method of conventional visual inspection, but this method is very not objective. To measure the width, length, position, direction of a crack, it is very difficult, when the tunnel is long span and high rise. Thus, to make up for this demerits, in this paper is proposed the Tunnel Scanning System that we can check conditions of the tunnel structures quickly, detect the detailed data objectively, count automatically the width of a crack by the original software and follow the trend of long tenn changes in the condition of a tunnel.

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Variable Angle Beam Guided Wave Probe Design for Tubing Based on Solid Mechanics

  • Cho, Youn-Ho
    • Journal of the Korean Society for Nondestructive Testing
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    • v.23 no.6
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    • pp.594-604
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    • 2003
  • A State-of-art methodologies on implementing conventional piezoelectric and flexible PVDF elements for generating ultrasonic guided waves in a tubing are presented. Comb transducers with PVDF can be efficiently applied to selectively excite a guided wave mode by wrapping around any size pipe while a conventional immersion type piezo-elements can be also possibly used with a modification of transducer fabrication. Technical comparisons between the use of angle beam probe and comb one will be also discussed in detail. The presented technique can be easily applied to NDE for a long range inspection of tubular structures.

Study of combinations of site operating states for multi-unit PSA

  • Yoo, Heejong;Jin, Kyungho;Heo, Gyunyoung
    • Nuclear Engineering and Technology
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    • v.53 no.10
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    • pp.3247-3255
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    • 2021
  • As Probabilistic Safety Assessments (PSAs) are thoroughly conducted for the Site Operating States (SOSs) for a single unit, multi-unit Probabilistic Safety Assessments (MUPSAs) are ongoing worldwide to address new technical challenges or issues. In South Korea, the determination of the site operating states for a single site requires a logical approach with reasonable assumptions due to the fact that there are 4-8 operating units for each site. This paper suggests a simulation model that gives a reasonable expectation of the site operation states using the Monte-Carlo method as a stochastic approach and deterministic aspects such as operational policies. Statistical hypothesis tests were conducted so that the reliance of the simulation results can be guaranteed. In this study, 7 units of the Kori site were analysed as a case study. The result shows that the fraction of full power for all 7 units is nearly 0.45. For situations when more than two units are not in operation, the highest fraction combination was obtained for Plant Operation State (POS) 8, which is the stage of inspection and repairment. By entering various site operation scenarios, the simulation model can be used for the analysis of other site operation states.

A Review on Meat Quality Evaluation Methods Based on Non-Destructive Computer Vision and Artificial Intelligence Technologies

  • Shi, Yinyan;Wang, Xiaochan;Borhan, Md Saidul;Young, Jennifer;Newman, David;Berg, Eric;Sun, Xin
    • Food Science of Animal Resources
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    • v.41 no.4
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    • pp.563-588
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    • 2021
  • Increasing meat demand in terms of both quality and quantity in conjunction with feeding a growing population has resulted in regulatory agencies imposing stringent guidelines on meat quality and safety. Objective and accurate rapid non-destructive detection methods and evaluation techniques based on artificial intelligence have become the research hotspot in recent years and have been widely applied in the meat industry. Therefore, this review surveyed the key technologies of non-destructive detection for meat quality, mainly including ultrasonic technology, machine (computer) vision technology, near-infrared spectroscopy technology, hyperspectral technology, Raman spectra technology, and electronic nose/tongue. The technical characteristics and evaluation methods were compared and analyzed; the practical applications of non-destructive detection technologies in meat quality assessment were explored; and the current challenges and future research directions were discussed. The literature presented in this review clearly demonstrate that previous research on non-destructive technologies are of great significance to ensure consumers' urgent demand for high-quality meat by promoting automatic, real-time inspection and quality control in meat production. In the near future, with ever-growing application requirements and research developments, it is a trend to integrate such systems to provide effective solutions for various grain quality evaluation applications.

A re-appraisal of scoring items in state assessment of NATM tunnel considering influencing factors causing longitudinal cracks (종방향균열 영향인자 분석을 통한 NATM터널 정밀안전진단 상태평가 항목의 재검토)

  • Choo, Jin-Ho;Yoo, Chang-Kyoon;Oh, Young-Chul;Lee, In-Mo
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.21 no.4
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    • pp.479-499
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    • 2019
  • State assessment of an operational tunnel is usually done by performing visual inspection and durability tests by following the detailed guideline for safety inspection (SI) and/ or precision inspection for safety and diagnosis (PISD). In this study, 12 NATM tunnels, which have been operational for more than 10 years, were inspected to figure out the cause of longitudinal cracks for the purpose of modifying the scoring items in the state assessment NATM tunnel related to the longitudinal crack and the thickness of concrete lining. All investigated tunnels were classified into four groups depending on the shape and usage of each tunnel. The causes of longitudinal crack occurrence were analyzed by investigating the correlations between the longitudinal crack and the following four factors: the patterns of ground excavation; construction state of primary support system; characteristics of material properties of the concrete lining; and thickness of lining which was obtained by Ground Penetration Radar (GPR) tests. It was found that influencing factors causing longitudinal cracks in the lining were closely related with the construction condition of the primary support system, i.e. shotcrete, rockbolt, and steel-rib; crack occurrences were not much affected by the excavation patterns. As for the properties of concrete lining materials, occurrence of the longitudinal crack was mostly affected by the following three items: w/c ratio; contents of cement; and strength of lining. When estimating the lining thickness of the concrete lining by GPR tests and taking thickness effect into account in the statement assessment, it was concluded that increase of the index score by an average of 0.03 (ranging from 0.01 up to 0.071) is needed; a more realistic way of state assessment should be proposed in which the increased index score caused by lack of lining thickness should be taken into account.

Management of Infrastructure(Road) Based On Asset Value (자산가치 기반의 교통인프라 유지관리)

  • Dong-Joo Kim;Woo-Seok Kim;Yong-Kang Lee;Hoon Yoo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.28 no.3
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    • pp.100-107
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    • 2024
  • Currently, in Korea, due to the rapid aging and deterioration of facilities, the minimum Maintenance Level and Performance Level' of facilities are required by the 'Facility Safety Act' or 'Infrastructure Management Act'. Since infrastructure assets have a long lifespan and the pattern of deterioration over time is complex, it is very difficult to maintain infrastructure as 'minimum maintenance state' or 'minimum performance state' by the current way of management. 'Asset Management' shall be performed not only by a technical perspective, but also by an accounting perspective such as cost and asset value. However, due to lack of awareness of 'asset management' among stakeholder, only technical perspective management is being carried out in practice. In order to effectively manage infrastructure assets, complex consideration of various asset value factors such as budget and service as well as safety and durability are required. In this paper, we presented a theory to evaluate and quantify the road network value for efficient asset management of the road network. We also presented a method of simulation to apply the theory presented in this paper. Through simulation and the results derived from this study, it is possible to specify the budget for the future national asset management, and to optimize the strategy for the management of old road facilities.

Productivity Improvement by developing statistical Model

  • Shin Ill-Chul;Park Jong-Hwan
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2002.05a
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    • pp.225-231
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    • 2002
  • POSCO $\#2$ Stainless steel making plant produces more than 600 thousand ton per year with a variety of products consisting of austenite and ferrite stainless steel to meet custrmers' needs since 1996. The plant has four different major processes, that are, EAF-AOD-VOD-CC to finally produce semi-product called as slab. In this study, we importantly took AOD process into consideration due to its roles such as to check and verify the final qualities through sampling inspection. But the lead-time from sampling to its verification takes five to ten minutes causing produrtivity loss as muck as the lead-time as a result. Of all indices for quality and process control the plant has, carbon ingredient in liquid type of steel is the most important since it affects in a great way to the characteristics of steel, if any problem. customers not satisfied with quality could issue a claim; therefore there is no way hut to guarantee it before delivery. in this study, to reasonably reduce lead-time ran save a cycle time and finally improve our productivity from a state-or-art alternative just such as applying statistical model based on multi-regression analysis into the A.O.D line by analyzing the statistical and technical relationship between carbon and the relevant some vital independent variables. In consequence, the model with R-square $87\%$ allowed the plant to predict, abbreviating the process in relations to sampling to verification. approximately the value of [C] so that operators could run the process line with reliability on data automatically calculated instead of actual inspection. In the future, we are going to do the best to share this type of methodology with other processes, if possible, to apply into them.

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Lmbr1 Expression in Early Embryo Development Stages in White Leghorn and Chinese Silky

  • Zhang, Ying;Xu, Weizhuo;Li, Ning
    • Asian-Australasian Journal of Animal Sciences
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    • v.22 no.1
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    • pp.7-12
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    • 2009
  • Lmbr1 is regarded as a key gene that controls the digital model formation in early developmental stages of the chicken. However, there are few reports of lmbr1 expression levels and tendencies in 4-toe and 5-toe chicken species. Therefore, the objective of this study was to compare the lmbr1 expression in White Leghorn (4-toe) and Chinese Silky (5-toe). Firstly, total RNA was extracted from 14 different embryonic development stages (HH3 to HH31) in White Leghorn and Chinese Silky. Secondly, dramatic gene expression changes of lmbr1 were monitored by RT-PCR, which indicated a general up-down-up tendency with subtle differences between these two species. Moreover, Q-PCR reactions were performed to quantitate the expression level of lmbr1 in the 14 selected developmental stages. These data demonstrated a first lmbr1 expression peak of 18.68 and 15.32, a lmbr1 expression trough of 6.61 and 1.80, and a second lmbr1 expression peak of 22.33 and 12.48 in White Leghorn and Chinese Silky, respectively. Finally, embryonic in situ hybridization analysis identified that lmbr1 expressed in the ectoderm in HH21, HH23 and HH24 developmental stages in both species.