• Journal of Auto-vehicle Safety Association
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• v.13 no.2
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• pp.42-49
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• 2021

In this paper, we proposes a study on the derivation of inspection factors for the periodic inspection of large buses equipped with AEBS and LDWS. we investigate the safety evaluation (NCAP) of domestic and foreign vehicles and safety standards for the two functions currently in operation and analyze the evaluation factors, measurement methods and evaluation scenarios and so on. In addition, the test scenario was derived by analyzing the vehicle safety evaluation data already held, Therefore, we use an real large bus and the inspection elements for the periodic inspection were derived.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.599-604
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• 2018

For missile systems, sustaining high reliability and ensuring economical maintenance are very important. In the Republic of Korea, for most missiles, periodic inspection is mandatory for missiles in the field. Every fixed number of years, they are returned to the ordnance depot to be tested and repaired if faults are found. Almost all missiles have a built-in test (BIT) capability. With the BIT, faulty missiles can be isolated anytime during operations or storage in the launchers. So the reliability and the maintenance costs of the missiles greatly depend on the length of the inspection cycle and the BIT/inspection quality. In this paper, we suggest a model for predicting the storage reliability of missiles subjected to non-periodic tests and periodic inspections, excluding overlapping failures. Some numerical examples are given. This model will be useful for determining the length of the periodic inspection cycle.

• Communications for Statistical Applications and Methods
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• v.15 no.3
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• pp.387-402
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• 2008

In this thesis we propose a two-stage periodic inspection model for maintaining the reliability of a system in long-term storage. There are two types of tests available; a fallible test and an error-free test. The system is overhauled at detection of failure or when the storage reliability after inspection becomes less than or equal to the prespecified value. The expected cost per unit time until overhaul is derived and a procedure for minimizing the expected cost is suggested. The two-stage periodic inspection model is compared with the one-stage periodic inspection model for various parameters of the cost function when the failure time follows exponential and Weibull distributions. The proposed model is then applied to an existing missile system for comparison with the current inspection policy.

• Journal of the Korean Data and Information Science Society
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• v.23 no.4
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• pp.843-850
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• 2012

The inferences of data obtained from periodic inspection and type I censoring for the three step stress accelerated life test are studied in this paper. The failure rate function that a log-quadratic relation of stress and the tampered failure rate model are considered under the exponential distribution. The optimal stress change times which minimize the asymptotic variance of maximum likelihood estimators of parameters is determined and the maximum likelihood estimators of the model parameters are estimated. A numerical example will be given to illustrate the proposed inferential procedures.

• Journal of Auto-vehicle Safety Association
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• v.16 no.1
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• pp.42-48
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• 2024

With a sustained increase in the number of reported registrations for two-wheeled vehicles and the simultaneous growth of the domestic two-wheeled vehicle market, fueled by the activation of contactless industries and a rising population engaging in recreational two-wheeled vehicles during the COVID-19 era, concerns regarding safety incidents and environmental issues have come to the forefront. While the regular inspection methods and environmental standards for four-wheeled vehicles are becoming more stringent for safety and environmental management, the same cannot be said for two-wheeled vehicles. As the market for two-wheeled vehicles continues to expand, there is a pressing need for improvements in the management and inspection of these vehicles. In this study, we analyze cases of non-compliance from the results of periodic inspections over the past five years, specifically focusing on illegal customizations, exhaust emissions testing, and exhaust noise results. Through this analysis, we elucidate the necessity for enhancing the inspection system for two-wheeled vehicles, drawing parallels with the inspection systems applied to conventional automobiles. The findings of this research contribute to advocating for improvements in the inspection regime for two-wheeled vehicles, addressing the growing concerns related to safety and environmental impact.

• Journal of the Korean Data and Information Science Society
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• v.20 no.6
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• pp.1169-1175
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• 2009

In this paper, the inferences of data obtained from periodic inspection and type I censoring for the step-stress accelerated life test are studied. The exponential distribution with a failure rate function that a log-linear function of stress and the tampered failure rate model are considered. The maximum likelihood estimators of the model parameters are estimated and also the optimal stress change time which minimize the asymptotic variance of maximum likelihood estimators of parameters is determined. A numerical example will be given to illustrate the proposed inferential procedures and the sensitivity of the asymptotic variance of the estimated mean by the guessed parameters is investigated.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.1
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• pp.142-147
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• 2018

Private electrical facilities are judged whether it is suitable for the insulation aging condition of their incoming underground cables using DC leakage current test method. In the case where the service point of utility is the secondary side of cut out switch installed in the electric pole, there is a problem that it is difficult to separate the lightning arresters(LA) because of their high position of the pole. Therefore, the field test voltage is applied at value lower than DC 30 kV, which are stated in the inspection guideline. However, this test could reduced the insulation performance of the LA by accelerating the electrical stress of the metal oxide varistor element in the pre-breakdown region. In this study, we analyzed the relationship between the DC test voltage and the leakage current using the non-destructive DC high voltage equipment with leakage current measurement function. The results show that the leakage current increases sharply above the specified test voltage. As a consequence, it could be contributed to improve insulation aging inspection method by selecting the possible test area on the VI characteristic curve of the pre-breakdown area of the LA.

• Journal of the Korea institute for structural maintenance and inspection
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• v.3 no.1
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• pp.113-120
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• 1999

Due to the heterogeneous nature of a concrete, periodic inspections are compulsory to maintenance of quality of concrete structures. The major object of this study is to analyze and investigate experimentally the experimental equation for the estimate of compressive strength of prestressed concrete. In this study, surface hardness method, ultrasonic method are investigated to evaluate strength of concrete specimens. Specimens are cast in laboratory and cores are cut from specimens in order to estimate the accurate strength. These values are used to compare with calculated values from test data. The result shows that the proposed equation can reproduce the results at prestressed concrete beam girders more appropriately than previous equations.

• Journal of the Korean Dietetic Association
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• v.20 no.1
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• pp.36-49
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• 2014

This study evaluated the effectiveness of a visiting inspection and knowledge-based food safety education program for cooks in child care facilities provided by the Center for Children's Foodservice Management (CCFSM). The research was conducted among cooks at 91 child care facilities; 56 existing facilities had been enrolled since 2011 and provided with the inspection and education program for 2 years and 35 new facilities were enrolled in 2012 and provided with the program for 1 year. The food safety knowledge of the cooks of the two groups were compared by the presence and duration of inspection and education programs provided by the CCFSM. The total mean score for food safety knowledge was $18.48{\pm}3.09$, with a group score of $19.34{\pm}2.68$ for the existing facilities and $17.11{\pm}3.25$ for the new facilities (P<0.001). There was no significant difference between groups in the knowledge of the personal sanitation. According to a post-test for food safety knowledge in the two groups after the completion of a one-year program on food safety by CCFSM, the mean score of food safety knowledge increased by 2.92 to 20.03 for cooks of the new facilities and both groups had significantly higher mean scores than pre-test (P<0.001). There was no significant difference in the mean score of each group by post-test. Thus, the one-year continuous program by CCFSM was effective in improving food safety knowledge of the cooks of the child care facilities.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.2
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• pp.152-158
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• 2003

A machine-vision guided inspection system with go-no gauges for inspecting eggcrate assemblies in steam generators is considered. To locate the gauge at the right place, periodic corrective actions for its position and traveling direction are required. We present a machine vision algorithm for determining inserting position and traveling direction of the go-no gauge. The overall procedure of the algorithm is composed of camera calibration, eggcrate image preprocessing, grid-height adjustment, intersection point estimation between two intersecting grids, and adjustment of position and traveling direction of the gauge. The intersection point estimation is performed by using linear regression with a constraint. A test with a real eggcrate specimen shows the feasibility of the algorithm.