• Structural Engineering and Mechanics
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• v.15 no.5
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• pp.551-562
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• 2003

This paper presents a procedure for designing feedback controllers for defective systems with repeated eigenvalues, and also for a nearly defective system with close eigenvalues. For the nearly defective system, we first transform it into a defective one, and then apply the same method to deal with the nearly defective system. A method for computing the gain matrices is discussed here. The methodologies proposed are based on the modal coordinate equation to avoid the tedious mathematical manipulation. As an application of the present procedure, a numerical example is given.

• Structural Engineering and Mechanics
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• v.27 no.5
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• pp.527-540
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• 2007

The modal controller of single-input system cannot stabilize the defective system with positive real part of repeated eigenvalues, because some of the generalized modes are uncontrollable. In order to stabilize the uncontrollable modes with positive real part of eigenvalues, the multi-input system should be introduced. This paper presents a recursive procedure for designing the feedback controller of the multi-input system with defective repeated eigenvalues. For a nearly defective system, we first transform it into a defective one, and apply the same method to manage. The proposed methods are based on the modal coordinate equations, to avoid the tedious mathematic manipulation. As an application of the presented procedure, two numerical examples are given at end of the paper.

• Management Science and Financial Engineering
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• v.13 no.2
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• pp.141-157
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• 2007

In this paper, we address a design problem and a case study of a K-stage back-light-unit(BLU) inspection system, which is composed of K stages, each of which includes an inspection process and a rework process. Assuming the type I, II errors and the inspection-free policy for items classified as good, we determine the smallest integer of K which can achieve a given target defective rate. If K does not exist, holding the current values of the type I, II errors, we search reversely the defective rate of an assembly line and the defective rate of a rework process, to meet the target defective rate. Our formulae and methodology based on a K-stage inspection system could be applied and extended to similar situations with slight modification.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.2
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• pp.221-227
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• 2005

This study has suggested the base data for decision of maintenance ranking and estimation of maintenance effect in the maintenance project of sewers as based on investigation of the defective rate in the sewer through Infiltration/Inflow(I/I) and CCTV analysis. It also analyzed the correlation between I/I and defective rate of sewer. As the result of this study, (1) Defective items of sewer was found out one item each 12.97m with an average. (2) By regression analysis, I/I has high correlation with defective rate of sewer like that $R^2$ is 0.7806. (3) The first thing in the item with bad influence on the I/I was joint badness and secondary was cross connection.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.130-133
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• 2005

This paper presents the efficient method to detect the defective detectors of the SWIR band of SPOT 4. The key of this method are to flatten the baseline of the data using high pass band filter instead of differentiation. This method is made up six steps. First step is to apply image enhancement techniques to enhance the lines imaged by defective detector and improve the quality of an image. Second step is processed by summing the enhanced image in line direction. These summed data have the peaks that represent the defective detectors and the curved baseline characterized by the reflectivity of Earth surface. In order to exactly detect these peaks, third step is to flatten the curved baseline using high pass filtering in the frequency domain. In fourth step, the data with flat baseline is normalized to have zero mean and unity standard deviation. In fifth step, the defective detectors are detected using $99.9\%$ confidence interval. Finally, after removing the detected ones in summed data, the steps from third to five are iterated. Three SPOT 4 images, which have different reflectivity of Earth surface and different sensor, were used to validate this method. The overall accuracy of detection for three images was $97.9\%$. This result shows that this method can detect efficiently the lines made by defective detectors.

• International Journal of Highway Engineering
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• v.15 no.5
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• pp.157-166
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• 2013

PURPOSES : This study is to analyze expected effect of a accident decrease when motorcycle safety inspection is introduced. METHODS : Based on the literature review of effect of 4-wheel vehicle inspection, probability of occurring accidents among defective motorcycles are calculated by using the number of estimated defective motorcycles and accidents resulting from defects of motorcycles. Then, the number of decreased accidents which is resulting from eliminating defects of motorcycles by safety inspection is estimated by using probability of occurring accidents among defective motorcycles. RESULTS : If the ratio of eliminating defects of motorcycles is 95% after motorcycle safety inspection, the effects of accident decrease of motorcycle safety inspection are analyzed from 2005 to 2008. As a result, 46,292 defective motorcycles are repaired and 1,376 accidents are prevented when the probability of occurring accidents among defective motorcycles is 2.97%. CONCLUSIONS : This study suggests the expected effect of motorcycle safety inspection is that the inspection can prevent 1,376 motorcycle accidents. However, the number of preventing motorcycle accidents are small, compared with the total number of motorcycle accidents because there are limitations to investigate the causes of defective motorcycle accidents. A more precise analysis of the expected effect of motorcycle inspection is possible when a systematic investigation of the causes of the accidents is implemented.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.9 no.13
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• pp.13-16
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• 1986

In this paper we study the decision rule for the amount of purchasing materials according to the fraction defective in the single sampling inspection by attributes based on operating characteristics. In deciding the amount of purchasing materials, it is important that we ought to occupy the practical purchasing amount, considering the fraction defective of the lot in acceptance inspection, because the acceptance probability is variant with the fraction defective of the lot.

• Journal of Korean Society for Quality Management
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• v.30 no.2
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• pp.152-159
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• 2002

An acceptance sampling plan for products manufactured from a production process with variable fraction defective is developed. We consider a situation where defective products have short lifetimes and non-defective ones never fail during the technological life of the products. An acceptance criterion which guarantee the out going quality of accepted products is derived using the prior information on the quality of products. Numerical examples are provided.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.305-306
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• 2002

In this paper, the endurance life of the rolling bearings with defective balls and their failure (flaking) phenomena are presented. It was found that the lives of ball bearings with defective balls were shorter than that of calculated L10 life as well as that of normal bearings in spite of the using standard bearing components. Although the bearings were assembled with defective balls, whereas the other parts were qualified new ones, the main failures were occurred on the inner ring raceways. Moreover, the failures were on the center of the groove curvature and the severity of failure is similar to the order of initial defect depth of the balls. These shows that the defects on the bearings can affect the life of tribologically contacted mating parts.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.34
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• pp.3-26
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• 2007

Product liability law lies at the center of the modem world. This law concerns liability for damages arising from the commercial sale of a product that causes personal injury or property damage because it was defective or falsely represented. One engaged in the business of selling or otherwise distributing products who sells or distributes a defective product is subject to liability for harm to persons or property caused by the defect. In short, product defectiveness is the heart of products liability law. Regardless of the underlying cause of action, the plaintiff in nearly every products liability case must prove that the defendant's product contained an unnecessary hazard that caused the harm. The purpose of this paper is to clarify the meaning of the product defectiveness to products liability claims in China. In China, Product to include most movable personal property, but to exclude services. And a product is defective when, at the time of sale or distribution, it contains a manufacturing defect, is defective in design, or is defective because of inadequate instructions or warnings.