• Journal of the Korean Institute of Educational Facilities
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• v.14 no.4
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• pp.34-42
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• 2007

The investment of BTL(Build-Transfer-Lease) projects for the educational facilities has been increased since 2005. However, many trial errors and problems have been occurring due to the lack of inspection criteria in maintenance cost for the lift cycle of the facilities. Thus, purpose of this study is to derive regression equation for the daily inspection and the regular inspection through analysis of CAD data in order to set the inspection criteria. It is possible to calculate economical maintenance cost of BTL project in educational facilities using criteria of inspection time through the regression equation developed in this study.

• Journal of the Korean Society of Safety
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• v.27 no.4
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• pp.121-127
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• 2012

Vehicle Inspection System is to examine the condition of vehicle regularly at the national level to protect lives and properties of the people from traffic accidents due to vehicle's fault. However, the vehicle inspection method, criteria, period and effectiveness have become a controversial issue, because of examining safety management of vehicle by drivers regardless of regular vehicle inspection. Therefore, the aim of this study is to investigate vehicle inspection timeliness and risk level of inspection items through basic statistical survey and portfolio analysis. The results of the research through practical analysis are: (1) The inspection failure rates between 3 and 6 model year tend to increase. (2) The failure of inspection items for safety highly impacts on traffic accident rate in terms of accident risks. (3) According to the result of portfolio analysis, faulty items located 1st quadrant are riding device, driveline system, controlling device, steering actuator, and fuel system.

• Journal of Korean Institute of Industrial Engineers
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• v.35 no.3
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• pp.194-202
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• 2009

In this paper, we address an optimization problem and a case study for minimizing the cost of inspections incurred throughout an inspection system, which includes a K-stage inspection system, a source inspection shop, and a re-inspection shop. In order to formulate the inspection cost function, we make a time-based flow analysis between nodes (or shops), and derive the limiting sizes of flows between nodes and limiting defective rates by solving a set of nonlinear balance equations. It turns out that the number of items reworked throughout the inspection system is invariant irrespective of the defective rate of items moved through the K-stage inspection system. Hence we define the inspection cost as the total number of items inspected, and we provide an enumeration method for determining an optimal value of K which minimizes the number of items inspected.

• Journal of Korean Society for Quality Management
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• v.23 no.3
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• pp.69-83
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• 1995

In a large number of literature on of inspection tasks, one of the most consistent findings is the existence of large and consistent differences among inspectors. It is possible that the individual difference is described by the difference of cognitive skills, because cognitive skills are required more than manual skills in inspection tasks. Therefore, a set of cognitive factors in human information processing may underly human performance in inspection tasks. In this study, a cognitive skill was described as the relative importance of the cognitive factors involved. A hierarchical task analysis and a fuzzy hierarchical analysis were used to represent how the importance of cognitive factors contribute to inspection performance. An experiment was conducted using the computer simulations of PCB inspection tasks. The results revealed that the subject group with better performance showed the importance weights of cognitive factors in the following rank; (attention, perception, judgement, classification, recognition)<(detection)$\ll$(memory). The results of the experiment can serve as a selection criterion for efficient inspection performance and the information of skilled learning for an inspection training program. The usefullness of a hierarchical task analysis and a fuzzy hierarchical task analysis for the analysis of cognitive tasks are also confirmed.

• Industrial Engineering and Management Systems
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• v.16 no.1
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• pp.1-21
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• 2017

This paper discusses a reverse supply chain (RSC) which consists of the process flows from procurement of used products collected from a market, through remanufacturing products from the used products, to sales of the products in a market. In general, it is conceivable for the RSC to face the uncertainty in quality of used products collected from a market. Inspection is one of efficient methods to deal with the problem regarding quality of used products. However, there is a trade-off between inspection cost and inspection accuracy. This paper focuses on the following five types of inspection: (1) 100% inspection, (2) sampling inspection, (3) sampling inspection with screening of rejected lots, (4) sampling inspection with screening of acceptable lots, and (5) no inspection, and determines the optimal operation consisting of the optimal number of procured used products and the optimal inspection policy. Numerical analysis clarifies not only how changes of conditions of the RSC affect the manufacturer's optimal operation but also features of each inspection type. In addition, from the results of numerical analysis, this paper shows the usability to add the proposed inspection in this paper, the sampling inspection with screening of acceptable lots, to choices of inspection type.

• IE interfaces
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• v.24 no.1
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• pp.87-96
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• 2011

In this paper, we address an optimization problem for minimizing the inspection and rework cost in an inspection-rework system, which forms a network of nodes including a K-stage inspection system, storage areas for items, a source inspection shop, and a re-inspection shop. We assume that (n, 0) acceptance sampling is performed in the source inspection shop and that only 100(1-r)% of items of rejected lots are re-inspected in the re-inspection shop. Since all the nodes are interrelated, in order to formulate our steady-state objective function, we make a steady-state network flow analysis between nodes, and derive both the steady-state amount of flows between nodes and the steady-state fraction defectives by solving a nonlinear balance equation. Finally we provide some fundamental properties and an enumeration procedure for determining the optimal values of (K, r) which both minimizes our objective function and attains a given target average outgoing quality.

• Journal of Navigation and Port Research
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• v.31 no.2
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• pp.151-157
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• 2007

After World Trade Center's Terror in 2001 and promulgating Maritime Transportation Security Act (MTSA, 2002) and Security and Accountability For Every Port Act (SAFE Port Act, 2006) in the United States, most of the attention on security of international transportation including marine carrier and facility has focused increasingly. Inspection stations in foreign seaport terminal including Busan, South Korea, have been installed by Container Security Initiative (CSI) and Customs Trade Partnership against Terrorism (C-TPAT). The inspection station, however, may directly and indirectly affect delay of truck turnaround time in the seaport, especially high and severe level of security. This paper was analysed a risk for the additional average delay of truck turnaround time incurring by the inspection station under the all level of security, C-TPAT and CSI. As a result of this risk analysis, the higher weighted inspection time based on raising security level, the less number of trucks to be inspected, which will derive high delay in the inspection station.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.10
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• pp.1869-1873
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• 2010

For reliable operation of oil-filled electrical equipment, monitoring and maintenance of insulating oil is essential. Dissolved gas analysis(DGA) is widely used for monitoring faults in high voltage electrical equipment in service. Therefore, oil analysis should be monitored regularly during its service life. KEPCO has investigated thousands of dissolved gas analysis data since 1985, and conducted studies on the relationship of gas in oil analysis and internal inspection results of transformer. As the results, KEPCO revised criteria for transformer diagnosis and has applied it since 2008. Almost of 100 cases of internal inspection results since 2001 have been investigated. This paper presents the correlation of the fault-identifying gases with faults found in actual transformers and how should we approach to internal inspection of transformer by dissolved gas analysis.

• Journal of Navigation and Port Research
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• v.33 no.8
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• pp.589-594
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• 2009

The Major inspection is a ship inspection which is executed voluntarily for tankers by Major oil companies(hereinafter it is called "Major"). To take the Major's cargo tanker should pass Major inspection. Thus, even though Major inspection is executed voluntarily, it is more important one than any other inspection for ship's crews and owner because it is closely related to the business profit of shipping company. In this study, authors suggested the improving measures after checking the problems concerned with Major inspection through status analysis. For the status analysis, authors carried out a questionary survey and interview with the interested parties, such as tanker crews, persons in charge of shipping company and inspectors, as well as studied the related literature and statistics data.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.64 no.2
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• pp.45-49
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• 2015

This paper presents a quantitative analysis method to quantitatively indicate a electrical fire preventive effect of safety inspection for electrical facilities for general use. Logic model was developed based on whether enforcement of safety inspection for electrical facilities, and then the developed analysis model was converted to hydraulic model by using mathematical logic. The electrical fire preventive effect of safety inspection for electrical facilities was quantitatively calculated by applying electrical safety inspection results and fire statistics for five years to the developed hydraulic model. The results show that electrical fire preventive effects of 5,542 cases on annual average for five years.