• Journal of the military operations research society of Korea
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• v.37 no.1
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• pp.49-70
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• 2011

This paper re-evaluated the research on the accounting information's effectiveness in military construction contracts, questioning the former research results on the central army's construction contract that was under the Qualification Assessment System, especially concerning the relations between the accounting information and the bidding ratios as well as the relations between the bidding rates and the defect rates, which targeted between 1 to 10 billions civil engineering, construction, electricity, telecommunication, and environment work types. Unlike the previous results, the relationship between the accounting information and the bidding rates was shown to be considerably limited that the bidding ratio could not be identified through the accounting information, while it could discern the relations with the defect rates. Furthermore, the proven results did not support the hypothesis that the differences in bidding rates could affect the defect ratio. However, through the prediction model of bidding and defect ratios, we could identity the accounting variables that influenced the ratios. Additionally through the results regarding the non-financial indexes in the Pre-Qualification items, the weight on these indexes could be adjusted. In conclusion, the research results has given us new understanding of the problems in the Qualification Assessment System which accounts for the majority of the current military construction contracts and provide validity on the government's expanded implementation of the Lowest Price Award System.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.5
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• pp.198-205
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• 2005

Many precedent investigations hate been made for the reliable assessment of the insulation state of large power apparatus for which partial discharge detection is one of tile plausible way. In this work, experimental investigations have been carried out to make the comparison on the PD(partial discharge) pattern analysis related to the five different types of artificial defects such as SFMP (Single Free Moving Particle), MFMP (Multi Free Moving Particle), Void, CFP (Conductor-Fixed Protrusion), EP (Enclosure Protrusion). For each PD pattern, PD detection has been done by tee different types of PD sensors such as HFCT(High Frequency Current Transformer), AE(Acoustic Emission) and UHF(Ultra High Frequency). And, in addition, frequency spectrum by the UHF sensor has been also made for each defect respectively. As a result, it is observed that the possibility of obtaining PD pattern based on PRPD(Phase Resolved Partial Discharge) in connection with the defects tinder investigation is dependant on the type of the sensor while the spectrum analysis is always successful to be achieved for every defect. Therefore, it could be suggested that the nature of PD source can be identified more distinctively when the conventional PRPDA is combined with spectrum analysis.

• Journal of Welding and Joining
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• v.35 no.1
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• pp.55-60
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• 2017

There are many Industry Code and Standard (ICS) for Structural Integrity Assessment (SIA) on welded structure with defect. The general ICSs, such as R6, BS 7910 and API 579-1/ASME FFS-1, provide equations to determine the upper bound residual stress profiles based on collections from many literatures. However, these residual stress profiles used in the SIA cause the conservative design for welded structures. In this study, the structural integrity assessment for girth weld in pipeline has been conducted based on fracture mechanics. In addition, thermo-elastic plastic FE analysis was performed for evaluating the residual stress of girth weld in pipeline. The weight function solution is used to determine the stress intensity factor using the residual stress profile obtained by the FE analysis. This approach can account for redistribution and relaxation of residual stress as the defects grow. In order to the evaluate quantitative comparison between BS 7910 and weight function solution, structural integrity assessment determining allowable crack size on cracked pipe was performed with failure assessment diagram.

• Journal of Korean Society of Water and Wastewater
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• v.29 no.1
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• pp.123-131
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• 2015

A CCTV inspection method has been widely used to assess sewer condition and performance, but Korea lacks a proper decision support system for prioritizing sewer repair and rehabilitation (R&R). The objective of this paper is to introduce the results that we have developed in the Sewer Condition Assessment and Rehabilitation Decision-making (SCARD) Program using MS-EXCEL. The SCARD-Program is based on a standardized defect score for sewer structural and hydraulic assessment. Priorities are ranked based on risk scores, which are calculated by multiplying the sewer severity scores by the environmental impacts. This program is composed of three parts, which are decision-making for sewer condition and performance assessment, decision-making for sewer R&R priority assessment, and decision-making for optimal budget allocation. The SCARD-Program is useful for decision-makers, as it enables them to assess the sewer condition and to prioritize sewer R&R within the limited annual budget. In the future, this program logic will applied to the GIS-based sewer asset management system in local governments.

• Structural Monitoring and Maintenance
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• v.8 no.4
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• pp.361-378
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• 2021

While the pavement rating system is being utilized for periodic road condition assessment in the Eastern Region municipality of Saudi Arabia, the condition assessment is costly, time-consuming, and not comprehensive as only few parts of the road are randomly selected for the assessment. Thus, this study is aimed at developing a condition assessment model for a specific sample of a residential road network in Dammam City based on an individual road and a road network. The model was developed using the Analytical Hierarchy Process (AHP) according to the defect types and their levels of severity. The defects were arranged according to four categories: structure, construction, environmental, and miscellaneous, which was adopted from sewer condition coding systems. The developed model was validated by municipality experts and was adjudged to be acceptable and more economical compared to results from the Eastern region municipality (Saudi Arabia) model. The outcome of this paper can assist with the allocation of the government's budget for maintenance and capital programs across all Saudi municipalities through maintaining road infrastructure assets at the required level of services.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.8 s.251
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• pp.931-940
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• 2006

Defect assessment of a weld zone is important in fitness-for-service evaluation of plant components. Typically a J and $C^*$ estimation method for a defective homogeneous component is extended to a mismatched component, by incorporating the effect due to the strength mismatch between the weld metal and the base material. The key element is a mismatch limit load. For instance, the R6/R5 procedure employs an equivalent material concept, defined by a mismatch limit load. A premise is that if a proper mismatch limit load solution is available, the same concept can be used for any defect location (either a weld centre defect or a heat affected zone (HAZ) defect) and for any material combination (either two-material or multi-material combinations; either similar or dissimilar joints). However, validation is still limited, and thus a more systematic investigation is needed to generalise the suggestion to any geometry, any defect location and any material combination. This paper describes the effect of structural geometry on the $C^*$ integral for defective similar welds, based on systematic elastic-creep 2-D and 3-D finite element (FE) analyses, to attempt to elucidate the questions given above. It is found that the existing 'equivalent material' concept is valid only for limited cases, although it provides conservative estimates of $C^*$ for most of cases. A modification to the existing equivalent material concept is suggested to improve accuracy.

• Journal of the Korean Society for Nondestructive Testing
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• v.33 no.4
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• pp.323-329
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• 2013

This perform research of angle rated defect detection conditions and nuclear power plant piping defect detection by lock-In infrared thermography technique. Defects were processed according to change for wall-thinning length, Circumference orientation angle and wall-thinning depth. In the used equipment IR camera and two halogen lamps, whose full power capacitany is 1 kW, halogen lamps and target pipe's distance fixed 2 m. To analysis of the experimental results ensure for the temperature distribution data, by this data measure for defect length. Reliability of lock-In infrared thermography data is higher than Infrared thermography data. This through research, Shape of angle rated defect is identified industry place. It help various angles defect detection in the nuclear power plant in operation.

• Clinical and Experimental Pediatrics
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• v.45 no.12
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• pp.1546-1550
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• 2002

Purpose : The authors carried out this study to determine the relationship between vigabatrin (VGB) and visual field defect.. Methods : Seventy eight patients older than 8 years who had epilepsy which had developed and been diagnosed, and were receiving add-on therapy, were the subjects of this study. If suspicious results were obtained from the initial test with the Humphrey automatic perimeter, the patient was tested again with the Goldman perimeter. Follow-up examinations were performed on these patients after 6 months. Results : In this study, five of the 78 patients had suspicious primary test results, but upon the second examination they were all found to be normal. Thus there were no patients with visual field defects. Conclusion : VGB is a drug which may cause visual field defects, but in this study no patients presented with this symptom. Instead of limiting the use of VGB due to the adverse effect of visual field defect in the initial treatment of partial seizure and infantile spasm untreatable with other medication, if used with care it may not cause serious problems. Screening for visual defect is recommended, and in patients taking VGB regular examination is necessary.

• Journal of Chest Surgery
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• v.29 no.2
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• pp.147-152
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• 1996

his study was undertaken to assess the residual interventricular shunt following surgical closure of the isolated ventricular septal defect. From January 1989 through December 1993, 211 patients underwent surgical closure of the isolated ventricular septal defect. All patients had 2D-Echocardlo-graphic study after operation to rule out residual ventricular septal defect. There was a 9.5% incidence of a definite residual shunt. The type of ventricular septal defect, closure method of the defect and cardiopulmonary bypass time showed no significant differences between two groups. The sue of ventricular septal defect (6.3 $\pm$ 3.7mm versus 10.6 $\pm$ 5.8mm : p : 0.0034), aortic cross-clamping time(32.6 $\pm$ 15.0 minutes versus 48.5 $\pm$ 20.0 minutes, p : 0.0003), pulmonary-to-systemic pressure ratio(0.31 $\pm$ 0.22 versus 0.51 $\pm$ 0.33, p=0.019) and mean pulmonary artery pressure(20.3 $\pm$ 11.9 mmHg versus 29.1 $\pm$ 16.2 mmHg, p : 0.009) were meaningfully different between two groups. There were 9 insta ces of spontaneous closure of the residual shunts at mean 21 months of following up (ranged 1 ~43 months). In conclusion, we suggest that the size of ventricular septal defect, aortic cross-clamping time and mean pulmonary artery pressure may play an important role in occurance of residual ventricular septal defect.

• Journal of the Korean Society of Safety
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• v.21 no.4 s.76
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• pp.13-18
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• 2006

In spite of frequent defect in industrial boilers, life assessment or diagnostic method for them has not been actively studied. In this research, SS400 carbon steel used in industrial boilers is simulated with artificial aging heat treatment. To do qualitative life assessment, differences in micro-structures and hardness of SS400 by the degradation time are studied. In addition, variation in material properties by aging was observed with the tensile test at room temperature and $179^{\circ}C$ and changes in ductile to brittle transition temperature was observed with the charpy impact test performed at several test temperature.